Fitts' Law and Beyond
From IEOR 170 Spring 2007
Required Readings
- The information capacity of the human motor system in controlling the amplitude of movement by Paul M. Fitts, Journal of Experimental Psychology, volume 47, number 6, June 1954, pp. 381-391. (Reprinted in Journal of Experimental Psychology: General, 121(3):262--269, 1992).
- Beyond Fitts' Law: Models for Trajectory-Based HCI Tasks by Accot, J., Zhai, S., In Proc of ACM CHI 1997, p295-302.
Discussions
Please post your critiques/commments on the required readings below. To do that, first login by using your user name and password, then click the "edit" tab on the top part of this page (between the "discussion" page and the "history" page), New to wikis? Read the Wiki editing guide. . Hint - Please put a whole line == ~~~~ == at the beginning of your submitted critique, so the wiki system will index, sign and date your submission automatically.
[edit] Onyi Lam 12:04, 16 March 2007 (PDT)
"The information capacity of the human motor system in controlling the amplitude of movement"
The article starts off stating that we cannot study human’s motor system in isolation from its associated sensory mechanisms but to continue with the discussion, the author ran the experiment based on the assumption that the responses are “highly overleaned” and the relevant stimulus conditions are held constant. The author then goes on discussing two observations on the relationship between the amplitude and duration of ballistic movements that are in conflict with each other. Three experiments are then reported in which were designed to test the relationship between the average duration responses and the minimum average amount of information per response demanded by the task conditions. The results supports that the performance capacity of human motor system is relatively consistent across a range of different tasks. So how does this result help the designers to design their products? I think that if the designer is asked to design a product that requires great precision and accuracy, she/he has to be pay attention to the optimal performance range of human motor system and make adjustments accordingly, especially if it is to fulfill ergonomic requirements.
"Beyond Fitts' Law"
This paper aims to investigate how Fitts’ law can be applied beyond pointing tasks. Fitts’ Law gives us a formal relationship that models speed/accuracy tradeoff but it only addresses one type of movement. Four experiments were then set up to address trajectory-based tasks, which are found mostly in computing input device. The results of these experiments align with our intuition that as the difficulty of the tasks increase, the speed of the movement decreases. I found the section about Design implication most interesting and most relevant to our class topics. A formula was given to model the time it takes to select the nth submenu and it can be served as a means to compare different menu designs. It also states what is the optimal ratio of the width and height of the menu bar to minimize the time needed. While this article is very interesting and there should exists a lot of design opportunities, I found it hard to apply to our design schemes. And even though it is good to have a quantitative relationship that describes our design and the users’ responses, I wonder if that makes a huge difference.
[edit] Asmita Karandikar 17:20, 17 March 2007 (PDT)
“The Information Capacity of the Human Motor System in Controlling the Amplitude of Movement”
This article explores the relations between speed, accuracy, and amplitude in relation to the precision of movement. The author hypothesizes that the error of visually-controlled movement increases both with amplitude and speed. To explore this hypothesis, the author uses three experiments that test different types of movements – tapping, transferring objects by grasping a washer and removing it from a pin (requiring finger movement), and transferring pints from one set of holes to another (requiring grasping and releasing, along with arm movements.) All three experiments indicated that performance (in bits/second) is relatively constant over a central range of amplitude and accuracy conditions, but increases as amplitude was decreased and accuracy criteria were extended. I think this is somewhat intuitive, as it is easier to complete a task correctly if you take more time to do it, and also because it takes more time to complete a task if it requires more movement, since your movements will usually be at similar speeds. It was interesting to read that industrial engineers were already using this idea when saying that one should use movements with small amplitudes in assembly work, since the time required to complete a unit of work increases as a function of amplitude and precision. However, besides this example, I would have liked to see this article give more information regarding how this information was being used, or could potentially be used.
“Beyond Fitts’ Law”
This paper discusses how Fitts’ Law, which was once sufficient to study Human-Computer-Interfaces, cannot be applied to more complex human-computer interactions, such as producing trajectories, and the authors attempt to find a simple mathematical model similar to Fitts’ Law to describe these movements. Fitts’ Law says that there is a tradeoff between speed and preciseness when pointing for aimed movements such as pointing. The authors conduct experiments involving steering between boundaries (or, constrained motion.) The author describes the experiments and mathematical models of the results, which I found to be a little confusing. The authors were successfully able to come up with mathematical relationships between movement time and target width, movement time and “tunnel” width (the width of a path when steering.) Finally, the authors conclude that steering time and difficulty are linearly related. I think that this information can be useful when designing interfaces because it will allow the designers to create the interface in such a way that it is easy for the user to accurately use.
[edit] Siu Pan Lam 19:44, 18 March 2007 (PDT)
“The Information Capacity of the Human Motor System in Controlling the Amplitude of Movement”
The experiment described in this article depicted the capacity of the human motor system. Specifically, by performing a controlled experiment, the experimenters were able to claim that performance is limited mainly by the capacity of the human system. In the article, three tasks were analyzed: reciprocal tapping, disk transfer, and pin transfer, and the results from all three experiments supported the author’s hypothesis – that the rate of performance of all three tasks increased as movement amplitude was decreased. While I was reading the article, I was a little confused about the relationships between speed, accuracy, and amplitude as these terms were not clearly defined. As a result, I was not able to mentally picture how the tasks were performed in the experiment. One idea that came up to me while reading the article was how to apply the results from the experiment into industrial design. In industrial design, we want to create something that can be manipulated effectively and efficiently, and studying the influence of tasks varying in parameters can provide some insights on achieving this goal.
“Beyond Fitts’ Law: Models for Trajectory-Based HCI Tasks”
The beginning of this paper focused on the inadequacy of Fitts’ law in describing trajectory-based tasks. Fitts’ law was actually described in the previous article on information capacity on the human motor system. This law states the relationship that models speed/accuracy tradeoffs in aimed movements. In addition, this article clarified the ambiguity that I had about the previous article on human movement – the faster we move, the less precise our movements are. Four experiments were analyzed in the article to validate the quantitative relationships between completion time and movement constraints in trajectory-based tasks: goal passing, straight tunnel, narrowing tunnel, and spiral tunnel – the latter task with the highest level of complexity. The variables analyzed were amplitude (tunnel length) and variability (tunnel width). One thing that I liked about this article comparing to the previous one was that it talked about GUI design implications with links to the experiments performed. For example, the use of menus in current GUIs involved something similar to a linear path steering task. Using the results from the straight tunnel experiment, one can model the time needed to select a sub-menu as the sum of vertical and horizontal steering tasks.
[edit] Esha Datta 20:25, 18 March 2007 (PDT)
"The information capacity of the human motor system in controlling the amplitude of movement"
It was interesting to hear the details of the experiments which were conducted in order to establish Fitts' Law and to establish a relationship between speed and accuracy when conducting certain types of tasks. It was interesting that they were able to create a formal equation to define the relationship and to see that the conclusions make sense on an intuitive level. I would expect that response rates would mainly be affected by tolerances and amplitudes. I am curious to how Fitts' Law can affect design and would be interested in seeing some concrete examples of this principle in use.
"Beyond Fitts' Law: Models for Trajectory-Based HCI Tasks"
This article showed that the Fitts' Law could also be applied to several different types of tasks than the ones that already been originally tested. It was interesting to see the implications of Fitts' Law in design and specifically in human computer interaction, such as in menu selection. It would be really interesting to see how Fitts Law affects design of physical products and how this information could be beneficial in helping to create new innovative products.
[edit] Andrew prasetyo 00:47, 19 March 2007 (PDT)
“The Information Capacity of the Human Motor System in Controlling the Amplitude of Movement”
The author mainly explains how to measure the relationship between human perceptual sensory and motor system. The author further emphasizes this relationship by providing three different experiments, i.e. Reciprocal Tapping, Disk Transfer, and Pin Transfer. These experiments quantify the response rate in relations with the given condition, i.e. particular amplitude and tolerance. One important result of the experiments is that “the performance capacity of the human motor system plus its associated visual and proprioceptive feedback mechanisms” will remain constant under different conditions. It is an interesting result because it shows how human body can adjust itself to respond to different conditions. As a result, it would be useful to note this result and implement it in industrial design because the design’s interface will determine the user’s motor response time and accuracy.
“Beyond Fitts’ Law: Models for Trajectory-Based HCI Tasks”
This article is an extension of the first article about the Fitt’s law of how human motor response will be associated with the visual stimulus and feedback. In this article, the author also introduces a new concept, called “steering tunnel.” This concept is to test the accuracy of human motor response, such as handwriting, in a limited space. Similar to the first article, in order to test his hypothesis, the author uses different experiments, i.e. Goal Passing, Increasing Constraints, Narrowing Tunnel, and Spiral Tunnel. I like the way the author mentions about design implication, i.e. how this concept can be used in Graphical User Interface which can be found in many electronic devices today, because designers can determine the interaction time when user is using the menu. Despite all that, I preferred to skip some of the mathematical details because some of the calculations are difficult to digest.
[edit] Johannesleholm 01:31, 19 March 2007 (PDT)
“The Information Capacity of the Human Motor System in Controlling the Amplitude of Movement”
This article really blew me away, and I mean that in probably every sense of the expression. Getting inside and understanding human ability is really pretty awesome to know while doing our group project. The authors in this article hope to prove that humans are more error prone when the amplitude of their movements and speed increase. This makes a lot of sense -- so much of it that I probably would of taken it as fact without reading (and taking thorough notes) about these experiments they did. But I'm pretty happy they did the experiments. The authors actually perform three distinct experiments: the infamous tapping experiment, the finger pin experiment, and finally the arm-swinging, pint carrying experiment. Long story short they found that errors increased with increased amplitude and speed, but decreased when accuracy ranges elongated. I'm going to have to remember this while making my award winning pizza pies. I mean, this really goes back to Napoleon’s divide and conquer strategy; splitting long, painful and thankless tasks into smaller pieces not only gives our minds a little boost, but also increases our accuracy.
“Beyond Fitts’ Law”
I didn't quite know if I was ready for this article; the road up to Fitts' Law was a bit shaky and trouble enough, and now we're expected to go beyond Fritts law? Well I certainly wasn't going to go on an empty stomach, so I cut a thick slice of my award winning cake and poured a tall glass of milk. Little did I know this had everything to do with the article I was about to read. You see, the authors of this article have made it abundantly clear they have little regard for Fritts and his revolutionary ideas. They intend to one up him and they intend to do it thoroughly. This really makes the Perelman thing look like a Sunday afternoon rode rage. Anyway they're looking at more sophisticated models to study human computer interaction. They decide to set up these steering experiments that measure accuracy of the user during certain circumstances. What they find is nothing less than fantastic; time to accomplish a task and its difficulty are positively correlated. Even more, it's linear. So how does that glass of milk and award winning cake fit in with this article, you ask? Well, I pour fast, and cut faster. Today I pushed myself to hit a new record and ended pouring all this vitamin D milk over the place.
[edit] Shilpi Verma 01:41, 19 March 2007 (PDT)
“The Information Capacity of the Human Motor System in Controlling the Amplitude of Movement”
This paper is about the human motor system, and the author uses various examples to explain and extend more information on the human motor system. The motor system utilizes visual and perceptive feedback to monitor a person’s activities. The experiments that the author describes are limited to motor tasks that have specified amplitude of movement. The paper’s thesis is a hypothesis that the experiments hoped to prove. The hypothesis dealt with amplitude and tolerance limits of the tasks are controlled and the subject is told to work at their fastest pace, then the average response time is directly proportional to the minimum average of the information required by the conditions of amplitude and tolerance. All the experiments that were performed showed that performance of a given task never reaches a maximum and is basically constant over a range of movements and tolerances. These results supported the hypothesis of performance capacity and feedback mechanisms remaining constant. The fixed capacity of the motor system’s capabilities to monitor movement is responsible for this result.
“Beyond Fitts’ Law: Models for Trajectory-Based HCI Tasks”
Fitts model predicts the time needed to point to a target of a certain width (W) and at a certain distance (A) is logarithmically related to the inverse of the spatial relative error (A/W). Fitts’ law is a sufficient way to study Human Computer Interfaces (HCI). Performance scores can be influenced by Fitts’ law. Without Fitts’ law performance scores are only meaningful under a set of specific experimental conditions, but with it they can be converted into a performance index. Four experiments were performed to derive and validate the quantitative relationship between completion and movement constraints in trajectory-based tasks. The first experiment was goal passing, where there were constraints only at the ends of movements. The second experiment was increasing constraints; the third experiment was narrowing tunnel, which was testing linear trajectories with a non-constant path. The fourth experiment was the spiral tunnel, where a new configuration was studied (the spiral tunnel). The results of all these experiments essentially followed the principle that as the difficulty of the tasks increase, the speed of movement decreases. The author then goes on to discuss design implications and how when a person interacts with currents GUI’s, they often implicitly perform various steering paths. In conclusion, Fitts’ law is one of the few laws that can be applied to HCI research and design.
[edit] Brian Loo 01:48, 19 March 2007 (PDT)
“Information Capacity of the Human Motor System in Controlling the Amplitude of Movement” The main point of the article was to demonstrate the capacity of the human motor system with respect to movement and it’s relationship to task involving a particular limb, muscle and motor behavior. His first experiment was with reciprocal tapping which required his test subjects to tap on 2 metal plates with a stylus. The second experiment required the test subjects to transfer 8 plastic discs from one pin to another. The final experiment was pin transferring which required moving a set of pins from one location to another specified location. The final result from these test is that performance stayed the same in a given tolerance range. In addition, the experiments pointed out that one’s rate of performance increases as the amplitude decreased. Not having such a great background as the reading required and stated from the start, I got easily confused and had to re-read this article for understanding. I thought it raised an interesting point, but did a poor job of communicating it for our level of knowledge and background. I wish it used similar terminology or at least explained it a little more.
“Beyond Fitt’s Law: Model for Trajectory-Based HCI Tasks” The main point for this article was to explain and apply steering law in relationship to movement that Fitt’s law (previous article) does not meet. The article performs four experiments to test and show how Fitt’s law doesn’t apply to users performance with a computer and other trajectory based tasks. The main point of Fitt’s law was the tradeoff between speed and accuracy with aimed movement. All the experiments to support this theory were goal passing which tested accuracy for connecting two vertical lines with another line. Each experiment varied with different challenges or constraints, such as a narrow tunnel, spiral, limited space, and unlimited space. Overall, this article was a lot clearer then the Fitt’s one and made it easier to understand. This is seen from the start with the well developed introduction and comparison to Fitt’s law. However, in the previous article, it just jumped right into the mathematical concepts.
[edit] Anar Joshi 01:55, 19 March 2007 (PDT)
The Information Capacity of the Human Motor System in Controlling the Amplitude of Movement: This article focused on completing various experiments in order to test the hypothesis about the correlation between speed, amplitude, and accuracy. The author indicated that the relationship between these three variables is one that people have studied, but it is not always applied. An example that was used to describe its importance was how industrial engineers advocate using small amplitude movements in assembly work to increase precision. The experiments that were conducted confirmed the author’s hypothesis, while the author also took into account that the results could vary for different movements, limbs, and muscle groups. I think this study is interesting when considering product usability.
Beyond Fitt’s Law: Models for Trajectory-Based HCI Tasks: This article discussed Fitt’s Law in relation to human-computer interaction. Similar to the first article, this one also conducted various experiments to test whether Fitt’s Law could be readily applied to HCI. I was most intrigued by the section that examined the design implications of modeling interaction time when using menus. The authors suggested a formula to use when creating hierarchical menus that involve two linear paths. If there are n submenus, there is a proportional relationship between n and the ratio of width to height in the menu. This is a practical application of Fitt’s Law and something that I didn’t realize that designers considered.
[edit] Timothy Manglicmot 09:03, 19 March 2007 (PDT)
[edit] The Information Capacity of the Human Motor System in Controlling the Amplitude Movement
This article mainly discusses the relationship between the human perceptual sensory system and the human motor system. In the article, the author describes three experiments which were run to evaluate the response times and average response times in various tasks – an experiment using finger movements, an experiment using arm movements, grasping, and releasing, and an experiment using arm movements, grasping and releasing. The main result of the tests was that as the amplitude of movement and the rate of speed decreased, the rate of performance increased. Also, as the range of accuracy gets longer the rate of performance also increases. This result can be very useful as it relates to design. For example, when engineering the design for a jump shot in basketball, by decreasing the amount of movement and speed at which it is released, basketball players can have a more accurate jump shot. Additionally, in relation to the accuracy range, statistically as jump shooters in basketball shoot further from the basket, generally their shooting percentage decreases. This is just one of the many applications of the results discussed in this article as it relates to design.
[edit] Beyond Fitts’ Law
Fitts’ law is a model relating the benefit-cost tradeoff between accuracy and speed. This article discusses Fitts’ law and observes its application through four different experiments. The results of the experiments were all consistent with Fitts’ Law, namely that as the tasks become increasingly more difficult, the rate at which the tasks are performed decrease in relation. Later the article discusses how Fitts’ law can be used in the design of graphical-user interfaces, and although this can be useful in design, I found that this had no relevance to me in terms of my design project or future ambitions. That being said, I also thought that Fitts’ Law as discussed in this article was very similar to the concepts introduced in the previous article. I think that Fitts’ Law is a basic human intuition that we all have in the back of our minds but seeing it being formally studies and quantified helps us build a deeper understanding of the concept.
[edit] Christine Shih 09:15, 19 March 2007 (PDT)
"The Information Capacity of the Human Motory System in Controlling the Amplitude of Movement"
This article studies the relationship between man's motor system and amplitude, speed, and accuracy. The following hypothesis was tested: If the amplitude and tolerance limits of a task are controlled by E, and S is instructed to work at his maximum rate, then the average time per response will be directly proportional to the minimum average amount of information per response demanded by the particular conditions of amplitude and tolerance. This hypthothesis was evaluated over 3 tests: reciprical tapping, disc transfer, and pin transfer.The results of the tests proved that the rate of performance increased uniformly as movement and amplitude was decreased and tolerance limits extended- which basically proved the hypothesis.
"Beyond Fitt's Law"
Fitt's law models speed/accuracy tradeoffs in aimed movements. It predicts that time T needed to point to a target of width W and distance A is logarithmically related to the inverse of the spatial relative error A/W and reveals that the faster we move, the less precise our movements are and the more severe the constraints, the slower we move. Several experiments were done to evaluatethe relationship between completion time and movement constraints in trajectoy based tasks: Goal Passing, Increasing Constraints,Narrowing the Tunnel,and Spiral Tunnel.
I didn't find either one of these articles terribly interesting cuz i felt that they proved the intuitive.
[edit] Bryan Boling 10:26, 19 March 2007 (PDT)
“The Information Capacity of the Human Motor System in Controlling the Amplitude of Movement”
This article provided information on the response rate and accuracy of the human motor system by performing tests with multiple individuals. Although all of these tests required only the use of the arm, and fingers for grasping, many generalizations were made about the performance of the human motor system based on the findings. I think these tests are fine for predicting the response of other tests using other muscles and movements, but without further testing these findings have to stand alone. Also, the author’s ultimate goal was to fit the test results to Weber’s law in order to mathematically model the human motor system response time and accuracy. While this is all very interesting to the right individual, I didn’t find any reason why I should be interested in the end results. This article did not provide any feedback on how this information could be used in design, or even how it affected peoples’ abilities to perform everyday tasks. Overall, I thought the article was ok, but not very useful.
“Beyond Fitt’s Law”
This article was a very good follow-up to the previous article. It also studied the relative accuracy of Fitt’s law in providing an accurate mathematical equation for predicting the response of the human motor system. Unlike the previous article however, this article was focused on human computer interaction (HCI), and there were many examples of how these studies could be used in trajectory based movement applications such as selecting the wanted path in a GUI. By extending the focus of the study to trajectory tasks rather than just pointing, the author was able to relate the results of the study to many computer based tasks. In doing this he was able to provide many possible applications of using Fitt’s law in HCI design, which is very useful now when computers are more widely used.
[edit] Aubuchon 10:53, 19 March 2007 (PDT)
“The information capacity of the human motor system in controlling the amplitude of movement”
In this article the author sets out to test a hypothesis that precision of human movement is a function of speed, accuracy, and movement. He uses three tests to investigate this- reciprocal tapping, disc transfer, and pin transfer. He ended with mean results of 0.613, 0.585, 0.578 seconds per movement for each test respectively. Movement times increased as the tolerance requirements and amplitude was increased. These results are quite intuitive to me, though these are interesting methods scientifically demonstrating the hypothesis.
“Beyond Fitts’ Law”
This article gives a mathematical representation of the tradeoff between speed and accuracy in a certain type of human movement. The article then tries to study speed and accuracy tradeoffs in other types of movement such as “trajectory based hcl” tasks (mainly computing tasks). I thought it was interesting about how the article gives a way to predict time to access sub-menus. I thought this could be used in conjunction with GOMS to simulate human timing on computer tasks.
[edit] Richard Chen 14:29, 19 March 2007 (PDT)
“The Information Capacity of the Human Motor System in Controlling the Amplitude of Movement”
Even though I felt that this article was a bit too technical for me, I still got some nice insights and understadning out of it. In particular, I was fascinated by the fact that there exists a theory of how human performance on certain motor tasks increases as movement amplitutde decreases, as the tolerance limits are simultanenously increased. By experimenting with a wide variety of subjects, the researchers found a definite correlation between the response reate and the accuracy of the human motor system. And these theories, I feel, are very useful for engineers as well as designers who must take into account the physical conditions for workers in production lines. Also very fascinating to me is the fact that these theories would tremendously help improve the efficiency and the throughput of companies’ manufacturing and production arms, which goes to show how design not only plays a major factor in determining whether or not the workers are working ergnomically or not, but also in improving businesses as a whole. Furthermore, the author’s discussion on Weber’s Law was something new to me—how the we could mathematically model the human motor response time and accuracy—this has tremendous applications to the world of design and much more.
“Beyond Fitt's Law: Models for Trajectory-Based HCI Tasks”
After reading, I am finally clear out what Fitt’s Law is about, how it is a model for human movement, in order to predict the time required to rapidly move from a starting position to a final target area (but as a function of the distance to the target and the size of the target). I am also glad to learn that Fitt’s law is one of the very few robust and quantitative laws that can be applied to human-computer interaction research and design. The applications of the law are just tremendous, as a great number of studies have been conducted to verify and apply Fitt’s Law. I liked how the authors’ were able to carry out and test the law by first demonstrating the logarithmic relationship between movement time and how the tangetial width of target in a tapping task can also exist between movement time and normal width of the target in a goal-passing task. The main takeaway that I got out of the article was how Fitt’s Law nicely equates the tradeoffs associated with how when speed increasese, the precision of the movement decreases. A basic principle like that is extremely useful when designing human computer interfaces and has numerous applications to improve the products for our end-users.
[edit] Connie Ko 12:08, 19 March 2007 (PDT)
"The Information Capacity of the Human Motor System in Controlling the Amplitude of Movement"
This article discusses the theory of how the rate of a person's performance on motor tasks increases as movement amplitude decreases and as tolerance limits are increased. There were a series of experiments (tapping, disc transfer, and pin transfer) that helped support this theory that were described in this article. I particularly found where they mention how Industrial Engineers take this reasoning into account when designing worker movements in production line-smaller amplitude movements result in faster production rates. I think that this concept is very useful in design especially in manufacturing environments where physical labor is involved. For example, at one of the companies I am working with, they are constantly concerned about ergonomics and efficiency in production. One of the solutions they came up with allowed a worker to push a button on a machine to close it rather than manually do so. This not only increased efficiency, but prevented arm injuries from performing the same "pulling" motion over and over again.
"Beyond Fitt's Law"
This article acknowledges that Fitt's studies have had a significant impact in the study of Human-Computer interaction. However, since the movements studied were so limited, this article further studies more complex movements, like trajectories. The author describes four experiments that were performed to study trajectory-based tasks: Goal Passing, Increasing Constraints, Narrowing Tunnel, and Spiral Tunnel. These experiments once again reinforce the theory that speed of movement is proportionally related to difficulty of task. Though this concept seems almost intuitive, I never really noticed how it could affect design before. I will definitely pay more attention to it in designs from now on.
[edit] Marshall Anderson 12:11, 19 March 2007 (PDT)
“The Information Capacity of the Human Motor System in Controlling the Amplitude of Movement” I thought this article was too advance for this course. I had a hard time reading the paper and I did not get much out of it. I guess the important thing to remember is that the “performance” of the motor system is relatively constant over a range of different task conditions but drops off at the extremes. But I noticed that the data does not indicate longer times for the smallest amplitudes. As amplitude decreases we expect by Fitt's law that the time would decrease but accuracy must increase so that distinction of position can be made. I assume that the amplitudes they used were not small enough to explore this territory.
“Beyond Fitt's Law: Models for Trajectory-Based HCI Tasks”
I was disappointed that the paper focused on HCI applications since this class is not an HCI class. I would have much rather read a similar paper on different motions that commonly occur with physical interfaces. However it was not that difficult to associate the tunnel steering task to something like controlling a two axis robot through several goals. This paper was easier to read than the first I did like the fact that there was a design implications sections at the end which helped to bring practicality to the picture.
[edit] Rakesh Vij 12:43, 19 March 2007 (PDT)
The Information Capacity of the Human Motor System in Controlling the Amplitude of Movement: This paper utilizes experiments to extend information theory to the human motor system. It is impossible to study the human's motor system at the behavioral level in isolation from its associated sensory mechanisms. The motor system is defined as the system that utilizes visual and perceptive feedback to monitor one's own activities. The information capacity of the motor system is calculated from measures of the variability of successive responses. The experiments discussed are limited to motor tasks that have a specified amplitude of movement. The thesis of this paper was a hypothesis that the experiments hoped to prove. The hypothesis basically stated that if the amplitude and tolerance limits of a task are controlled and the subject is told to work at his fastest pace, then the average response time is directly proportional to minimum average of the information demanded by conditions of amplitude and tolerance. The first experiment two subjects were asked to rectangular metal plates alternately with a stylus. The tolerance and amplitude were controlled by altering the width and distance of the plates. The results showed that users were more accurate using flexor over extensor movements. The other experiments were: transferring plastic washers from one pin to the other and to transfer pins from one set of holes to another. The results from these experiments show that performance of a given task is essentially constant over range of movements and tolerance, but never reaches its optimum level. The optimal level found varied between 10-12 bits/sec. The results, and the consistency of in range, supports the hypothesis that performance capacity and feedback mechanisms of the human motor system are constant over a considerable range of task conditions. The author attributes this result to the fixed capacity of the motor system's ability to monitor and organize movement.
Beyond Fitts' Law: Models for Trajectory-Based HCI Tasks This reading discusses the Fitts model in detail. The model is used ot predict the time needed to point to a certain width at a certain distance. It shows that this is logarithmically realted to the inverse of the spatial relative error. This law provides a sufficient way to study the Human Computer Interfaces (HCI). The Fitts' law provides some influential help with performance scores. Without the law these scores only have meaning under a specific set of conditions. With the help of Fitts law these scores can be converted into a performance index. To validate the quanititative relationship between completion and movement constraints, a set of four experiments were performed. The first was one that involved goal passing. In this experiment there were constraints only at the end of movements. The second was competed with increasing constraints, the third was with a narrow tunnel, and the last onw as with the spiral tunnel. The results helped prove the principle that as the difficulty of a task increases the speed decreases. This law has some profound impact on design, and especially when dealing with GUIs. The Firrs law is great and can be applied to HCI and help with design.
[edit] Rey Doctora 12:57, 19 March 2007 (PDT)
“The Information Capacity of the Human Motor System in Controlling the Amplitude of Movement”
This reading reveals how speed, accuracy, and the amplitude of the job being performed affect precision and movement. The article furthermore uses three tests to test the author’s hypothesis that error of movement increases as a function of both amplitude and speed: a reciprocal tapping test, a disc transfer test, and a pin transfer test. I found it interesting when the author states that industrial engineers have “consistently advocated that small-amplitude movements be used whenever possible in assembly work, on the grounds that the time required to complete a unit of work increases as a function of its amplitude as well as of the precision demanded by the task.” Having work as an Industrial Engineering intern, this is a concept I have internalized when watching assembly workers at a manufacturing company. The workers typically like to have easy, repetitive work which makes it easy for them to complete a task. Furthermore, as the workers work on a product that becomes more difficult to produce, they tend to take longer because of the inherent complexities and precision requirements of the product.
“Beyond Fitts’ Law”
This article reveals how Fitts’ Law has become somewhat outdated in today’s modern world. Before, Fitts’ Law was sufficient to study HCI but in today’s modern world of increasing complexity, the law is overly simplistic such as when attempting to describe more complex HCI, modeling trajectories, and movements in 3D space. The writers describe several experiments trying to model movement such as a pointing, and make it clear that there is a tradeoff in movement when setting speed and preciseness. Although I personally found the equations somewhat difficult to follow, I think this was a good overall article because it at least makes it clear that when designing an interface, one should make the interface easy enough for the user to have accuracy. Considering the limitations now imposed on Fitts’ Law, designers should be aware of the complexities inherent in today’s modern designs.
[edit] Patricia Wang 13:12, 19 March 2007 (PDT)
“The Information Capacity of the Human Motor System in Controlling the Amplitude of Movement”
This article analyzes the human motor system and its ability to generate one type of movement consistently, also known as its information capacity. The information capacity is evaluated based on consistency of the statistical metrics used to measure the movements. In this particular study, the information capacity is tested to determine its independence from the amplitude and permitted variability for a specified movement of one set of muscles. Like with some of the past articles, I think it’s really interesting that what I would have assumed to be relatively abstract concepts can be modeled mathematically and whatever conclusions are drawn are down so empirically.
“Beyond Fitts’ Law”
Fitts’ law essentially highlights the tradeoff between the speed and accuracy of a relatively specific movement, which involved hitting a target. He ultimately concluded that as the speed increase, the precision of the movement decreases. This article moves beyond the movement used in Fitts’ experiments and into tasks based on trajectories. It continues to test the relationship between the amplitude (tunnel length) and variability (tunnel width) and the time it takes to traverse through the path. Each of their experiments aligned nicely with the conclusions drawn from Fitts’ experiments.
[edit] Michael Chen 13:48, 19 March 2007 (PDT)
“The Information Capacity of the Human Motor System in Controlling the Amplitude of Movement”
Given that the sole author of the article is Paul Fitts, we can pretty much assume that this is the original paper that gave birth to Fitt's Law. While the article's writing style is relatively dense and confusing, the diagrams and the summary at the end really clarify the point of the article. If you think about it, Fitt's Law was actually of secondary consequence in the article. The real aim of Fitt's paper was to show that movement time is independent of information flow, not to derive an equation that defined movement time. Just goes to show that the stuff that makes you famous are sometimes really unexpected.
“Beyond Fitts’ Law”
I really liked this article, in that it was a extension of a simple concept that proves really useful, and it's really easy to understand. Instead of Fick's movements of finding a point, the experiment required the user to trace a line, which requires a continuous output, rather than a relatively discrete one. I thought that the GUI example that they provided at the end was an extremely practical application for their research. One thing that really surprised me was the extreme correlation that they found, with an R squared value of 0.96. That kind of uniformity is rare in human subjects, and I would have thought that there would be more variability.
[edit] Megan Whittey 13:28, 19 March 2007 (PDT)
“The Information Capacity of the Human Motor System in Controlling the Amplitude of Movement”
This article discusses the human motor system and how human performance is limited by the motor system’s capacity. The part that the article studied was the average amplitude, the average duration, and the distribution of successive amplitudes of a serises of rapid movements that and the person being tested attempts to produce with uniform aplitude. It tells us how the need for a unifying concept of motor capicity is given by the obvious difficulty of integrating many of the facts reported in the other reports of motor skills. The article discusses 3 experiments and their results. The first experiment people being tested were asked to tap two rectangular metal plates alternately with a stylus, one weighing one ounce and one weighing one pound. In the second experiment people were asked to transfer plastic washers from one pin to another. I found it interesting that in these two experiments, the only people that they tested were right-handed college men. In the third experiment people were asked to transfer pins from one set of holes to another, and in this one they tested both college men and women, and didn’t specify that they were right-handed at all. The results show that speed, amplitude, and tolerance are all interrelated. This article applies to us Industrial engineers when working and trying to optimize assembly lines because we realize that small-amplitude movements help make for a better production/assembly line. At first this article was a little confusing to read, but once I read it a second time it was a little easier to understand. I wasn't super engaged with it though.
“Beyond Fitt’s Law: Models for Trajectory-Based HCI Tasks”
This paper describes how Fitt’s law can apply to HCI tasks and derivation and the experiments that led to the steering law or local law. In Fitt’s law he found that there is a tradeoff between speed and accuracy, the faster you go the less accuracy you have and vice versa. With Fitt’s law people are able to use and compare it to HCI and performance index. Fitt’s conducted 3 main experiments that ultimately had to do with hitting a target over a certain distance and this applies to HCI by pointing and target selection. To address trajectory-based targets the 4 experiments done and discussed in this paper focus on steering between boundaries. This first experiment conducted was ‘goal passing’ which people were asked to draw a line on a computer from one goal to another and the results were much like the results from Fitt’s tapping task. The second experiment was ‘tunnel traveling’ where someone had to draw a line from one end of a tunnel to another. The third experiment was steering through a narrowing tunnel. And the fourth experiment was steering through a spiraling tunnel. I found it interesting that they didn’t specify or discriminate between right-handed or left-handed subjects like in the other article. They also didn’t specify whether they tested men or women or their age group like in the other paper. The last three experiments led to a global or local law that predicts the total time to perform a steering task and shows the relationship between velocity and path width. These studies can be applied to GUI’s and people who use menus on computers and so on. It can also be used to compare designs. I found this article easier and more interesting to read than the other one.
[edit] Christopher Ling 13:34, 19 March 2007 (PDT)
“The information capacity of the human motor system in controlling the amplitude of movement”
This rather technical article discussed the human motor system and its relationship with the “amount of information, noise, channel capacity, and rate of information transmission”. It summarized how the human motor system’s performance is relatively consistent. However, there is an increased error rate in visually-controlled movement when there is a increase in amplitude and speed. This makes a lot of sense because you will take longer to finish a task if the task requires more movement. The author supported this point by conducting three primary experiments. The three experiments that were conducted were “Reciprocal Tapping”, “Disc Transfer”, and then the “Pin transfer. The overall result in these experiments was that given a relevant tolerance range, the performance of the subject stayed relatively constant Also, they also reinforced the fact that the rate of performance increased as the amplitude decreased, which was consistent with the assumptions.
“Beyond Fitts' Law: Models for Trajectory-Based HCI Tasks”
Adding to the Fitt’s Law, this research applied the steering law to explore the “possible existence of robust regularities in trajectory based tasks”. The research added to the previous research by finding a better set of tools that described and tested motor control research. Again, the concept from the previous article was expressed in that a user’s precision decreased as the amplitude increased. Several experiments were conducted where subjects were asked to goal pass by connecting two vertical lines. The second experiment shows that the rate of error increased when the difficulty of the task increased, which was shown by increasing the number of constraints on the first experiment. Although this article provided more insight to Fitt’s Law, I felt it become too technical to easily understand in the end of the article
[edit] Michael Lovejoy 13:38, 19 March 2007 (PDT)
“The information capacity of the human motor system in controlling the amplitude of movement”
I did not like this article at all. It assumed basic familiarity with the concepts presented, but even if it seemed like I knew a little about the subject, it was extremely difficult to understand what exactly the article was trying to point out. However, the examples of the experiments performed helped a lot in understanding the points the author was trying to make. Because some of the ideas presented seem somewhat obvious to me (e.g. the more difficult tasks resulted in more errors), this article seemed pretty pointless. Some results were interesting (e.g. more undershooting than overshooting with the larger stylus, task performance increased more from first to second day than for second to third day), but no explanations for the reasons behind the results were presented. It seemed that all the experiments and data were simply presented to prove the point, and there is no possible evidence that could refute the author’s point.
“Beyond Fitts’ Law: Models for Trajectory-Based HCI Tasks”
I liked the article – it was well-written and presented its information in a very interesting fashion. I especially liked the introduction, which included a brief description of Fitts’ Law. I found this to be much more useful and informative than Fitts’ published article. To me, Fitts’ Law is simply and basic, intuitive description of human actions, and there are many applications and mathematical formulas that can be applied to make it more complicated. Zhai expands Fitts’ Law to address trajectory-based tasks. The descriptions of the experiments and the explanations of the results were very interesting and written in a simple manner. I also appreciated the section about design implications, which gave the results some real-world relevance. While I didn’t understand everything from the article, I certainly look forward to Dr. Zhai’s lecture today.
[edit] Yang Hung 13:57, 19 March 2007 (PDT)
"The information capacity of the human motor system in controlling the amplitude of movement"
The article is describing how to accurately measure the relationship between the human sensory system and the human motor system, it explores the relationship between speed, accuracy, and amplitude of movement as it relates to the movement's precision. The article states that one cannot study the motor system in isolation. But the experiments assume that when the responses are "highly over-learned" and all the outside stimulus is held constant, one can create a situation that is reasonable to estimate the motor system's capacity. The article then describes the three different experiments that the author ran: 1) reciprocal tapping, disk transfer, and pin transfer. An important result of the experiments is that the performance capacity of the motor system and its feedback mechanisms will be constant even under different conditions. The writing style of the article was a little dry but the experiments that the author ran seemed very interesting.
"Beyond Fitts' Law: Models for Trajectory-Based HCI Tasks"
This article extends the basic Fitts' Law equation into a model that can be applied to movement in two dimensions. In order to test for movement in two dimensions (as opposed to just one dimension in the traditional Fitts' law experiments), the author introduces the concept of a "steering tunnel," which is a way to test for the accuracy of a motor response in steering between boundaries. The author ran 4 experiments using this "steering tunnel" framework: goal passing, increasing constraints, narrowing tunnel, and a spiral tunnel. I really liked the fact that this article concludes with an application of their research in design. The authors discussed the design implications of their research when a user is interacting with a graphical user interface (GUI), since selecting a item from a menu involves two or more linear path steering tasks. This article was very well written and presented very logically.
[edit] Ricky Surachman 14:24, 19 March 2007 (PDT)
“The information capacity of the human motor system in controlling the amplitude of movement”
This article gives us information about how a human motor system works by showing examples of many experiment that has been done to various individuals to test their human motor system capabilities. although this article presents several interesting facts like movement times increases as the tolerance and amplitude of movement increases, overall I think that this article is too detail for our class.
“Beyond Fitts’ Law”
This article is a follow up of “The information capacity of the human motor system in controlling the amplitude of movement” article. In this article, the author discussed about the posibility of "robust regularity in trajectory task" which provides arguement on the inability of Fitt's Law to explain about some of the users' failed performance. To test that posibility, the author used some experiment like oal Passing, Increasing Constraints, Narrowing Tunnel, and Spiral Tunnel.
[edit] Erin Palermo 14:25, 19 March 2007 (PDT)
The Information Capacity of the Human Motor System in Controlling the Amplitude of Movement
I enjoyed reading this article. The relationship between speed, amplitude and accuracy was intriguing, when applied to movement precision. The fact that errors in visual movement increase with speed and amplitude makes sense, because it is more difficult to complete the movements. His experiments were neat, and the results really reflected this "law" of speed and amplitude. They showed that if you were slower and more controlled in your movements, then your precision improves. Fitt's Law is good, but I don't quite know how it is useful for design, other than to make the interface easy to manipulate.
Beyond Fitts’ Law
This paper answered my lingering questions from before about how to apply the law to design. But the paper claims that Fitt's law cannot be applied to complex HCI (human-computer interaction). They showed some intense mathematical models, and were able to represent mathematically the relationship between movement times and actions within a boundary, but it was a bit complicated. They studied mainly trajectory-based HCI, like computing tasks, which was kind of neat, because they could measure and predict times users would take to complete tasks like accessing menus. The experiments with connecting two vertical lines gave interesting results, in line with our expectations. I liked that they gave us design context at the end of the article.
[edit] James ChunJye Tong 14:28, 19 March 2007 (PDT)
"The Information Capacity of the Human Motory System in Controlling the Amplitude of Movement"
This article studies the human’s motor system. There are three experiments in this article that studies the motor system, they are reciprocal tapping, disc transfer, and pin transfer. These experiments show the relations between speed, accuracy, and amplitude and the human motor system. The more time it takes to do the job the more accurate the result will be and will require more movement. I don’t find this article very interesting because I think it is very obvious that the more time a person have to complete a disk, he would make less mistake. I don’t think this article provides useful information except for something that are obvious to everyone.
"Beyond Fitt's Law"
This article studies the trajectory-based interaction in Human-Computer-Interfaces, which is something that Fitts’ law does not apply. Examples of trajectory-based interactions include drawing curves and moving 3D objects. Fitts’ law says that there is a reverse relationship between speed and precision, and also the more constraints will cause slower movement. Fitts’ law only describes pointing targets. This studies uses four experiments to observe the trajectory-based interactions, they are goal passing, increasing constraints, narrowing tunnel, and spiral tunnel. The results of these experiments show that Fitts’ law does not apply to the trajectory-based interactions.
[edit] Shwan Kazzaz 14:33, 19 March 2007 (PDT)
"The Information Capacity of the Human Motory System in Controlling the Amplitude of Movement"
This article refers to a subject, S, whose motor system we wish to study. Through testing behavior of overly learned movements in rapid time-frames with uniform responses the article attempts to analyze the behavior of the entire receptor-neural-effector system. The article refers to experiments where movement amplitude varies and is measured. The article explains that amplitude, duration, and variability of movements are interrelated. When asked to make a finite increase in amplitude, experimenters found the duration of corrective movements monotonically increases as a function of amplitude. The article refers to three different experiments: Reciprocal Tapping, Pin Transfer and Disc Transfer. The evidence is clear that there is a relationship between amplitude, tolerance and speed, though it may only be a general one.
"Beyond Fitt's Law"
This article explains that point-based models, such as Fitt's law are inadequate in evaluating many of the three dimensional applications of motor systems which are trajectory based. It then explains through a series of steering experiments that new trajectory models can be generated. The article compares a tapping task with a goal passing task and the relationship therein between movement time and target width. There was also a correlation found in steering between tunnel width and movement time in three different models, including a spiral model.
[edit] Katherine Tong 14:55, 19 March 2007 (PDT)
"The Information Capacity of the Human Motory System in Controlling the Amplitude of Movement"
This article finds a relationship between amplitude, duration, and variablity of motor responses. Through three different experiments involving reciprocal tapping, disc transfer, and pin transfer a common trend was found. "The results indicate that rat of performance in a given type of task is approximately constant over a considerable range of movement amplitudes and tolerance limits." This was interesting because, even though the same muscle area was being tested, the types of motioned need for each experiment were not too similar.
"Beyond Fitt's Law" I enjoyed this article better because the experiments performed seemed more challenging. Rather than repeating several of the same motions, users were given a clear goal: get through the path with little error. The lack of repetitive muscle movements made the experiments seem more interesting to me. The experiments tested Fitt's Law, which states "the faster we move, the less precise our movements are, or vice versa: the more severe the constraints are, the slower we move."
[edit] Minhaaj Khan 15:14, 19 March 2007 (PDT)
The information capacity of the human motor system in controlling the amplitude of movement
Both the readings were very dense and seemed beyond the scope of what this class requires although I understand the importance of understanding the human motor system and incorporating the theoretical findings into the design process. The motor system is basically defined as, “including the visual and proprieties feedback loops that permit the subject to monitor his own activity.” The paper stressed that although we know that accuracy of quick movements decreases with amplitude, it is very important to understand movements through the close relation of speed, amplitude, and accuracy. Paul Fitts noted that Industrial Engineers have consistently advocated that small-amplitudes movements be used whenever possible in assembly work, because the time required to complete a unit of work increases as a function of its amplitude as well as by the precision demanded by the task. So clearly it is important to understand the theoretical and experimental findings of how the human motor system functions as this can play a very important role in a more efficient industrial design.
Beyond Fitts' Law
This article provides us with a more practical application of Fitts’ Law to design and discusses how Fitts’ Law is not and adequate model of trajectory based tasks/interactions (e.g. drawing, writing, steering) which are important as these are important tasks in the modern computer interface. Intuitively we understand that the difficulty of a task rises, the speed at which we perform the task decreases. Clearly this article is all about human-computer interaction and as I said earlier, although I can see the applicability, the detail is too much and totally unnecessary for the scope of this class. I feel like we can learn the basic points of these article and that is enough, and that the detail would only be necessary if you’re a graduate/PHD student interested in acquiring experimental and theoretical understanding of human-computer interaction (which is something the professor is all about).
[edit] Umber Masood 15:29, 19 March 2007 (PDT)
“The Information Capacity of the Human Motor System in Controlling the Amplitude of Movement”
This reading was interesting. Although it was a technical paper, it was easy to follow and understand. I agree with the results of the paper, that the more information there is to process, the harder it is and the longer it will take to do something. These results make sense.
I noticed that in the first and second experiments the 16 subjects were all right-handed college men. Then, in the third experiment, the subjects were 10 college men and 10 college women. I realize that the study was published in 1954, and female college students were most likely a minority on college campuses; however, I think that the first two experiments could have included women, as was done in the third experiment. The first two experiments could also not have been limited to right-handed people by including a few left handed people. Furthermore, it would be interesting to see the results of the experiments if there was more variability in the subjects’ ages, by not limiting the participants of the study to college students.
I realize that the paper was published in 1954 and that the US use inches and ounces as units of measurement, but I think that the study should have used metric units instead. In this way, international readers would be able to read the paper with ease and would not need to convert the units. The US did not make a decision to use the International System of Units (SI) until 1964, however, so Fitts’ use of inches and ounces is justified.
“Beyond Fitts’ Law: Models for Trajectory-Based HCI Tasks”
This paper was also an interesting read. It seemed to be slightly more mathematical in nature than Fitts’ paper. All of the experiments had very high r squared values, which surprised me because I did not think that they would be that high. Out of all the experiments, I liked the one in which subjects had to draw a spiral. The paper says that steering is “probably related to handedness.” It would be interesting to see the results of an experiment testing whether it is true that steering is related to whether a person is right-handed or left-handed. For experiments 2, 3, and 4 the paper has graphs of Speed versus Path Width. In all three graphs, I found it interesting that for higher path widths, the speed was not as predictable.
[edit] YeeWan Cheung 15:33, 19 March 2007 (PDT)
"The Information Capacity of the Human Motor System in Controlling the Amplitude of Movement"
The article starts off by pointing out we can only analyze the behavior of the entire receptor-neutral-effector system. The uniform results obtained by performing four tasks of the perceptual-motor activities enable the generalization the relationship between speed, amplitude, and tolerance. However, this is certainly a very hard to understand paper to me, and I am confused about the boarder application of this results.
"Beyond Fitts' Law: Models for Trajectory-Based HCI Tasks"
The purpose of this paper is to perform analysis and four experiments on the steering law, which is a beyond version of Fitts’ Law. Users’ performances in the trajectory-based interactions cannot be successfully modeled with Fitts’ law as the pointing task. The research found out there is a simple linear relationship between movement time and the “tunnel” width in steering tasks. The authors mention there is upper bound limits to the path width that can be correctly modeled by steering law due to the human body limitations. An example of a real life GUI interaction is the selection of an item in a hierarchical menu, which involves two linear path steering tasks. We can use this research to compare designs, and improve their performance.
[edit] Rabia Siddiqi 16:03, 19 March 2007 (PDT)
The Information Capacity of the Human Motor System in Controlling the Amplitude of Movement
This article was a research paper that decribed the process and results of an experiment involving the human motor system. The purpose of the experiment was to investigate the relationships between the human perceptual senory and motor systems, as well as between speed, accuracy and amplitude of motor responses. The conclusion that humans are most likely to make errors when the amplitude of their movements and speed are high was interesting. I didn’t really like the way the article was written because it became confusing and assumed that I knew more than I did. But I do believe that it is an good concept and very important for design usability.
Beyond Fitts' Law: Models for Trajectory-Based HCI Tasks
This is article talks about the Fitt’s Law in the context of human-computer interaction. Four experiments were performed and the results of all of them were consistent with Fitt’s Law, which says that as tasks become diffucult, the rate at which they are preformed properly decreases. I really liked the section that described how to predict time to access menus and submenus. Overall, Fitt’s Law is very useful when designing and improving human computer interfaces.
[edit] Patrick Liu 16:03, 19 March 2007 (PDT)
The Information Capacity of the Human Motor System in Controlling the Amplitude of Movement
This article details the human motor system. Human performance is dependent and also limited by the motor system’s capacity. The author discusses average amplitude, average duration, and uniform amplitude. The article discusses these topics with three experiments and results. The first experiment involved individuals tapping two rectangular metal plates alternately with a stylus. The plates varied in weight: one being one ounce and the other being a pound. The second experiment involved individuals to move plastic washer from one pin to another. The third experiment, instead of washers individuals were asked to transfer pins from one set of holes to another. The results of all three experiments tells us that speed, amplitude, and tolerance are all correlated in a manor that affects are motor abilities. I am neither really satisfied nor interested in many of the recent readings because they deal with very specific and technical aspects of our body rather than actual design concepts. I understand how these topics could affect design, but I would appreciate more engaging and interesting articles.
Beyond Fitts' Law: Models for Trajectory-Based HCI Tasks
This article details the applications of the “steering law” through four experiments. The first experiment was Goal Passing. Subjects were asked to use their mouse to pass from goal one to goal two as quickly as they could and results were recorded. The results showed that both the goal passing task and Fitts’ tapping task share the same laws but different nature of movement. The second experiment dealt with recursive analysis and the understanding of “neuromotor steering control process.” The third experiment was the narrowing tunnel. This experiment dealt with drawing a line through the tunnel as quickly as possible to understand if the method could be utilized in linear-trajectories but with a non-constant path. The results proved linear once again. The fourth and final experiment was the spiral tunnel. Basically the user had to try to draw a line from the center of the spiral to the outside without touching any of the lines of the spiral. Once again the predicted outcome was confirmed by even a slightly more complex task. Essentially Fitts’ these experiments confirmed that Fitts’ law is the quintessential law necessary for human-computer interaction research and design.
[edit] Royapakzad 16:13, 19 March 2007 (PDT)
The Information Capacity of the Human Motor System in Controlling the Amplitude of Movement
The article is about the human motor system and it examines the amount of information, noise, channel capacity and rate of information transmited during different tasks.I think the method for measuring the rate of information transmitted is fascinating(Weber-fraction), however I didn't really understand what "amplitude of motion" reffers to, for instance the amplitude of sound reffers to its loudness but what feature of movement are we discussing when talking about its amplitude? It was interesting to see how the results of the two observations on the relationship between the amplitude and duration of ballistic movements conflicted each other. Overall, I think the article was, to some extent, hard to follow, but it was interesting to find out that overall the performance capacity of human motor system is consistent among different tasks. I also think that the concept of human motor system is essential to designers, since they have to consider optimal performance range of human motor system when creating a new product, especially if it requires high precision.
"Beyond Fitts' Law"
This article discusses Fitt's law which provides a relationship that models the tradeoff between speed and accuracy of an aimed movement such as pointing. The author then performs experiments that suggest a mathematical model to replace Fitt's law.(since Fitt's law is no longer applicable for complex interactions between human and machines.) An importnat result concluded is that: as the difficulty and precision of a task increases, the speed of performance decreases. I think the study of human-computer interfaces is very essential for designers; however, the mathematical models suggested by the authors in this particular article are quite complicated.
[edit] Luciana Cook 16:21, 19 March 2007 (PDT)
"The information capacity of the human motor system in controlling the amplitude of movement"
I thought this article was interesting. It spoke about the relationship between speed, amplitude and accuracy. It dealt with movement pecision and discussed the human motor system and how human performance is limited by the motor system’s capacity. When thinking about what the artile was saying I found that sometimes his claims make sense and other times it doesn’t. I think that sometimes you get better outcomes if you do things slowly and precise, but there are things that have to be done quickly and still be as precise. This is useful when designing something. We hae to have in mind if people will use or product quickly or slowly and then asssimulate what the errors will be when using it quicly or slowly.
"Beyond Fitts' Law" I felt Fitt’s Law is hard to apply to a lot of designs today. I had a hard time relting it to my own examples. It talked about the relationship between the amplitude and the variability and the time it takes to traverse through the path. It mostly spoke about computing problems, which is an area I am not highly familiar with, but his conclusion were understandable since it wasn’t so technical.
[edit] Sumeet Patel 16:21, 19 March 2007 (PDT)
“The Information Capacity of the Human Motor System in Controlling the Amplitude of Movement”
I thought that this article was interesting because it talked about the human motor system. The article tested the interrelation of speed, amplitude and accuracy in performing motor tasks. One of the experiments he did was a task that dealt with arm movement and then grasping and releasing objects. The experiment shed light on the fact that performance increased when amplitude and speed of the arm decreased. These experiments make sense because the slower and more deliberate the action the more accurate.
“Beyond Fitts’ Law: Models for Trajectory-Based HCI Tasks”
This article discussed the interaction with Fitts’ Law and human-computer interaction, also know as HCI. I thought that this was a useful article because one of the experiments talked about was measuring the time to go through a menu. This is useful for me because my project in this class deals with creating software where the user will be interacting with menu’s. By using this article we could hypothetically reduce the amount of time a user needs to navigate through our software.
[edit] ChuiShan Wong 16:27, 19 March 2007 (PDT)
"The information capacity of the human motor system in controlling the amplitude of movement"
this article is an extended theory to the human motor system. It also tells us that we cannot study man’s motor system in isolation form its associated sensory mechanism. Then it talks about how human behaviors are affected by S. Furthermore, there are 3 experiments used to describe the relationship between the average duration responses and the minimum average amount of information per response demanded by the task conditions; as well as, they result point out that the level of optimum performance was fond to vary among 3 tasks I was a little bit confused with the “S” at the beginning, yet it is still an interesting article.
“Beyond Fitts’ Law”
This article talks about the relationship between the Fitts’ Law and human-computer interaction research and design. Also, in the article, it takes a few experimental steps to obtain and validate quantitative relationships between completion time and movement constraint in trajectory-based task. The four experiments are: Goal Passing, Increasing Constraints, Narrowing Tunnel, and Spiral Tunnel, they are mostly in computing input device. The results assist to prove the principle of as a difficulty of a task increases, the speed decreases. After clarifying all the experiments, it discusses about how it can implicate to design. This article is easier for me to understand than the previous one.
[edit] Nicolas Suryono 16:28, 19 March 2007 (PDT)
“The Information Capacity of the Human Motor System in Controlling the Amplitude of Movement”
This article provides interesting information about the human motor system. Based on the experiment conducted, it seems that the performance increased when the speed and the amplitude decrease. This is make sense because when we put more effort to the specified task, the success rate will decrease as discussed in class before.
“Beyond Fitts’ Law: Models for Trajectory-Based HCI Tasks”
I think this article is pretty interesting. It talked about the time that the user has to interact with menu and interface in a device. I think this is relevant to my own experience. I am always having a hard time navigating through the menus when I'm just starting to learn a new software. I think if the design can be made to make the user spend less time on navigating themselves through the menu, the user will have more productivity.
[edit] Tawan Udtamadilok 16:29, 19 March 2007 (PDT)
[edit] Ryan Jue 16:30, 19 March 2007 (PDT)
The Information Capacity of the Human Motor System in Controlling the Amplitude of Movement
This article was about human motor motion and how it can relate to design. The article discusses three different experience relating to human motor motion. The first experiment involved tapping two different iron plates with a stylus. The second experience involved moving washers from around one pin to another. The third experiment involved transferring pins from one hole to another. All of the experiments were designed to test the speed, accuracy and amplitude of the task being performed. This sort of relates to a lot of industrial engineering experiments involving task analysis for laborers.
Beyond Fitts’ Law: Models for Trajectory-Based HCI Tasks
This article was about how Fitt's Law is outdated in today's more complex society that involves trajectory in human computer interaction. "Steering through tunnels" was used as the premises for four experiment to be designed. The experiments were goal passing, increasing constraints, narrowing tunnel and spiral tunnel. Each of these were designed to show other regularities in movement tasks. I thought that the text in the article was really dense and a little complicated to understand. However, the diagrams made it a little easier to understand big picture concepts.
[edit] Justin Hsu 16:33, 19 March 2007 (PDT)
“The Information Capacity of the Human Motor System in Controlling the Amplitude of Movement”
This article “The Information Capacity of the Human Motor System in Controlling the Amplitude of Movement” discusses the relationship between the speed and the accuracy of human movement and how exactly they effect the precision. Three different movements were used to demonstrate his hypothesis. These movements included tapping, the washer/pin game, and the peg/hole game. The conclusions derived from these experiments made sense to me because it at the most basic level, the finding are intuitive. One would think that the performance of a human would be increased if he or she was allowed more time to complete a task. And while the time allotted decreased, I would think that the subjects accuracy would be affected adversely. This article also discusses how engineers today are utilizing this theorem in assembly lines to make them more efficient. Upon beginning to read this article, I was expecting another unintelligible research paper that I would have a very hard time understanding with little to contribute to the design concepts we have studied in this class. However, I was pleasantly surprised at how the article presented its material and the example it provided with its applications to factory assembly lines really gave me a sense of how relevant/useful the information was.
“Beyond Fitts’ Law”
The article “Beyond Fitts’ Law” was interesting because it really picked apart some of the concepts that we had just read in the previous paper. It goes on to list many instances in which Fitts' Law, once a reliable method to study and analyze HCI, is not sufficient for more complex tasks. The article attempts to derive a more robust equation that describes the speed/accuracy/amplitude relationship previously discussed by conducting a research experiment involving constrained motion with steering. It eventually discusses its findings but I found its derivations quite math intensive and I had a hard time following how exactly they went about formulating this conclusion. In the most basic sense, the article found that the steering time and the accuracy were in fact related. Unlike the previous article, I found this article difficult to understand. I did not take anything particularly new from this article other than some of the instances in which Fitts' Law fails to work. I thought the previous article did a better job of explaining some of the fundamental concepts regarding the how various parameters affect the amplitude of human movement.
[edit] Joshua Funamura 16:35, 19 March 2007 (PDT)
"Information Capacity..."
I thought that the experiments that Fitt conjured up were quite inventive in discovering the "information capacity" in human motor systems. It seems fairly intuitive that more difficult tasks are completed with more errors than simple tasks like in the reciprocal tapping experiment, but actually quantifying that difference and applying it to similar tests like the pin apparatus, makes it quite useful. I'm assuming this is the basis for Fitts Law, these findings have apparently been quite useful. In terms of interface design, it seems like it would be favorable to have multiple small tasks rather than a single complicated one (e.g. two or three clicks instead of a click and drag).
"Beyond Fitts Law"
I found this article to be pretty interesting, as it delved into more complex tasks of following a pointer through a tunnel of varying geometries, but was still able to reveal a coherent mathematical relationship between difficulty and time. I thought it was clever how they derived an actual difficulty 'amount' as a function of the width of the tunnel. An application became apparent, which they mentioned, for the navigation of nested menus in standard computer operating system GUIs. In my experience, traversing menus rapidly often causes the menu to be closed or adjacent menus to open, causing frustration. If software applications were optimized with these principles in mind, they might cause less user error.
[edit] Fenelia Kosasih 16:37, 19 March 2007 (PDT)
“The Information Capacity of the Human Motor System in Controlling the Amplitude of Movement”
This article involves the study of human motor system in terms of the amount of information, noise, channel capacity as well as the rate at which information is transmitted. Three experiments are done in this study: reciprocal tapping, disc transfer and pin transfer. In these experiments, the person are asked to make fast and uniform responses that have been overlearned, while holding all other relevant stimulus condition constant, except for the motor system in which the particular experiment is testing. Hence, the experiment measures the performance with respect to the capacity of the motor system. From the study, it is concluded that performance is relatively constant over the central range of amplitude and accuracy conditions. This relation is found to hold for most perceptual and motor activities. However, the capacity level of the motor system is found to vary with different kind of movements, limbs, and muscle groups. Even though the concept behind this article (quantifying the human perceptory system and motor system) is interesting, the article itself is boring, since it is presented as a form of a scientific journal. The concept is similar to the model human processor article, where how human minds work is modeled and quantified.
"Beyond Fitts' Law: Models for Trajectory-Based HCI Tasks"
This scientific journal studies and models trajectory based interactions, which includes actions such as drawing curves and moving in 3D worlds. Fitts' law, which has been used to model pointing tasks, has become insufficient to model such trajectory based interactions. The study uses "steering through tunnels" as an experimental example and discovered "steering law" in the process. The article gave some interaction examples and relates it to the steering law. A particular example is menu selection, which is modeled as a linear path steering task. The vertical portion and horizontal portion of the movement each has their own relation and equation, and the overall time needed to select the submenu is modeled as the sum of the time taken for the vertical and horizontal movement. Quantification of the time taken to select submenu in this manner is interesting.
[edit] Raymond Kim 16:42, 19 March 2007 (PDT)
“The Information Capacity of the Human Motor System in Controlling the Amplitude of Movement”
This article provided information regarding Human Motor Systems and their connection with sensory mechanisms. I found the experiments and studies quite interesting as they attempted to define upper and lower limits on the rate of certain human activities. By doing so, they were able to determine appropriate optimal levels of activity. As would be expected, increasing certain factors such as amplitude and speed dimished the success of acitivites. Experiments such as these give a greater insight into human capabilities and limitations, which are crucial factors to consider when designing products.
"Beyond Fitts' Law"
This article was a slight extension of the previous in that it discussed limitations on human activities, but it also focused mainly on human/computer interactions. Just like the previous article I found this to be quite interesting and humbling in the sense that even humans have limitations and restrictions on motor/sensory processes. Unlike many previous articles it appears that the experiments performed had much more practical and hard results which could be utilized when designing computer interfaces.
[edit] HAK-SEUNG KIM 16:48, 19 March 2007 (PDT)
Information Capacity of the Human Moter System in Controlling the Amplitude of Movement
In this article, the author demonstrates the man's motor system. Especially,he empasize that we cannot study man's motor system at the behaviroal level in isolation from its associated sensory mechanisms. Also the author shows many experiments to supprot human motor system in controlling the amplitude of movement; Riciprocal Tapping, Disk Transfer, Pin Transfer. I like the way that the author shows the method of experiment, results of the experiment even though it is somewhat hard to understand what the numbers indicates. Overall, this article is a lot informative and hardto understand the concept.
Beyond Fitts' Law: Model for Trajectory-based HCI Tasks
The author tells us the motivation, analysys, a series of four experiments, and the applications foth the steering law in this article. I got some idea of what the author want to demonstrate from the keywords part: fitts' law, human performance, modeling, movements, apth steering, motor contorling, input techniques and devices, trajectory-based interaction. Like the previous article,the author uses many experiments to support the model for trajectory-based HCI tasks; goal passing,increasing constraints, narrowing tunnel, and spiral tunnel. Instead he use statistics to conclude the results, the author derive the formula from the experiments. On the conclusion, he summerize that Fitts' law is one of the very few robust and quantitative laws that can be applied to human-computer interation research and design. Overall, this article is a lot informative and requires science background, so I have hard time understanding the article.
[edit] Hong How Quek 16:50, 19 March 2007 (PDT)
The Information Capacity of the Human Motor System in Controlling the Amplitude of Movement
This article reports how Fitts investigates the information capacity of the motor system, in particular its ability to consistently produce one class of movement from among several alternative movement classes. Fitts was also interested in a unifying concept of motor capacity which had not been apparent in previous literature. After a series of experiments such as reciprocal tapping and disc transfer, Fitts came up with a formula that measures how performance is affected by factors such as distance, which if Im not mistaken is later known to be Fitts Law. Although the law is somewhat intuitive (increased accuracy with time given, and increased time required for longer distances of movement), I think it is good that exact quantitative effects have been established so that designers/indsutrial engineers can plug in values to find out exactly (by what kind of factor- x2, x3?) will a change in product design/ergonomics affect performance index. However, the article is very theoretical and it would be better if examples are provided on how Fitt's findings can be effectively applied.
Beyond Fitts’ Law: Models for Trajectory-Based HCI Tasks
This article is basically a follow up to the previous one and it investigates exactly how accurate is Fitt's law (mentioned above) when predicting the human motor system response (ie. does the formula really reflect reality?). It is heartening to discover that Fitt's law is indeed very robust and accurate and as designers, we can apply it confidently in our prototyping and iteration processes (when designing HCI and other end-user applications). I found the 4 experiments used to study trajectory based tasks (Goal Passing, Increasing Constraints, Narrowing Tunnel, and Spiral Tunnel) to be very interesting, especially in the way they reinforced certain aspects of Fitt's theories, such as how speed of movement is proportional to task difficulty (higher difficulty, slower speed). Dr. Zhai's explanations were clear, concise and written in a very interesting manner and I look forward to attending the guest lecture today.
