Visual Perception and Visualization technique
From IEOR 170 Spring 2007
Required Readings
- Perception in Visualization Christopher G. Healey
Discussions
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[edit] Siu Pan Lam 18:06, 2 March 2007 (PST)
“Perception in Visualization”
This article begins with a discussion of preattentive processing, which is defined as “the ability of the low-level human visual system to rapidly identify certain basic visual properties.” While I was reading this part of the article, I felt that it was similar to one of visual perception experiments I did for psychology where the task was to read aloud the color of different words. For example, if you were given a display of the word “yellow”, but the word was printed in blue, then you were supposed to read aloud blue. This task was a little bit challenging because people are used to reading what the word actually says, instead of what the color of the word is. I think this is related to preattentive processing in that the recognition of what the word says is rapid and can be achieved without careful focus or attention. The interactive visual experiment given in the reading on the three different target detection searches (color, shape, and conjunction) was able to demonstrate the existence of preattentive processing in practice. I tried the experiment and I had the hardest time locating the presence of the target (red circle) when the target detection is conjunction (combination of blue circles and red squares). This makes sense because in the case of conjunction, the visual system is left with no unique visual property to search for when trying to locate the target. As a result, viewers will have to take more time to search through the displays to look for the target.
The four theories of preattentive processing were addressed to explain how preattentive processing occurs within the visual system. They are feature integration theory, texton theory, similarity theory, and guided search theory. Of these four theories, I found similarity theory by Duncan and Humphreys to be most useful and easiest to comprehend. The similarity theory is based on the resource allocation and the amount of competition for access to the visual short-term memory. It states that search time is based on T-N similarity and N-N similarity. If T-N similarity increases, then search efficiency decreases and search time increases. This makes sense because when the target and non-target objects are similar, it takes longer time to search for the target. If N-N similarity increases, then it takes less time to search for the target because one can easily reject large numbers of grouped structural units and hence can have more access to the short-term memory to search for the target.
Another interesting discussion that can be found in the article was on postattentive vision, which is mainly described as “What happens to the visual representation of an object when we stop attending to it and look at something else?” I was surprised to find that sustained attention to the objects did not make visual search more efficient because intuitively, it makes sense that the longer you tend to the objects the more efficient you are able to locate the target. The visual exercises given in the change blindness section were very interesting. For many of the images, I had trouble locating the changes in the images across the two frames. However, the changes became more noticeable when I looked at the whole image instead of staring at little details in the image. Overall, this article was an interesting read.
[edit] Timothy Manglicmot 15:34, 3 March 2007 (PST)
“Visual Perception and Visualization technique”
This article begins with a high-level overview of preattentive processing. According to the article these are visual properties detected very rapidly and accurately by the low-level visual system. This concept seems similar to several other concepts discussed in the course thus far, including affordances and mapping. For example, the use of the color green in the United States in a stoplight affords the concept of “go” in the human mind, and, similarly, green can be a preattentive process which can be distinguished by the human brain (among red and yellow) also signifying the concept of “go.” As it relates to design, these ideas can be very powerful when a designer is trying to map an idea out to the user without detracting his or her locus of attention from the main focus of the design. The article then describes specific details of preattentive processing with its four theories. This part of the article, although somewhat involved in terms of the reading, can be very useful as it gives detailed examples on how to use preattentive processing and what types of preattentive processing techniques actually work. These concepts should come in handy as it relates to our project design solutions. I also thought the part about the feature hierarchy to be especially interesting. The fact that humans can preattentively distinguish shapes and lines among other shapes and lines is noteworthy, but the idea that colors, for example, take precedence in visualization over shapes is a very interesting idea. In future designs I hope to integrate this idea by using color patterns to distinguish important ideas and by using other patterns to distinguish ideas of lesser importance.
[edit] Onyi Lam 00:10, 4 March 2007 (PST)
“Visual Perception and Visualization technique” is an very interesting read in which it explores the idea of preattentive processing and how it works in our visual system. This article starts of with the general introduction of preattentive processing and I found it very helpful to understand the concept with the pictures there, which specifically demonstrate how preattentive processing works in our brain. The author then goes off introducing four theories and they are feature integration theory, texton theory, similarity theory, and guided search theory. In the feature integration theorey, preattentive processing performances are measured by response time and accuracy. This is an intuitive approach and the researcher was able to come up with a table of visual features that can be preattentively detected. In the texton theorey, the researcher believes that only a difference in each texton can be detected preattentively. In the similarity theory, the researchers add that search time also depends on the number of items that needed to be identified and how easily can they be spotted. Finally, in the guided search theory, it can be characterized by an activation map which is composed by a top-down and bottom-up approach. Another interesting point in the article was the mention of first impression as an hypothesis to explain change blindness. The example it used was very interesting too. Nearly 2/3 of viewers cannot spot the character has been replaced by another actor and when asked to describe the main character, almost 70% described the initial actor, but not the replacement. I found it hard to believe that the audiences could not spot the character has been replaced. Did they delibarately use a replacement that looked very much like the initial actor?
[edit] Patrick Liu 11:49, 4 March 2007 (PST)
"Visual Perception and Visualization Technique"
This article details how understanding perception could improve quality and quantity of information. I found it interesting that the author displayed so many examples of visual properties using easy to understand pictures. There were examples of easily viewable differences in the pictures, but there were also examples of pictures that require the viewer to “perform a time-consuming serial search” in order to determine if the targeted object is present or not. The pre-attentive process consists of four models: feature integration theory, texton theory, similarity theory, and guide search theory. The feature integration theory approaches the pre-attentive task with two variables: response time and accuracy. After careful experimenting Triesman believes now that “parallel and serial represent two ends of a spectrum.” The texton theory focuses on “statistical analysis of texture patterns.” Julész found that “when oriented randomly in an image, one cannot pre-attentively detect the texture boundary between the target group and the background distracters.” I found similarity theory and guide search theory to be fairly uninteresting and not as useful as the integration theory. Change blindness is also quite interesting I believe that the existence of change blindness allows us to perceive cartoons or to perceive everything in life that is moving to be smooth. Without change blindness everything that we perceive would be choppy and would be similar to viewing everything in frames that are changed after long periods of time. Perception is very important to human factors and design because if the object being perceived gives off unperceivable notions then it obviously is a bad design.
[edit] Rey Doctora 12:41, 4 March 2007 (PST)
"Visual Perception and Visualization Technique”
This has been the most enjoyable article that I have read thus far. The article starts by describing preattentive processing and then attempting to explain preattentive processing through four different theories. The article then continues with insights on postattentive processing, feature hierarchy, change blindness, and concludes with descriptions on how color, texture, motion, and photorealism affect our visualization. I found the sections on preattentive processing and change blindness very interesting. In the tests for preattentive processing, I question how subjects were timed appropriately considering that the response times reported in the article were in milliseconds. Since the article mentioned that both accuracy and time were used to measure preattentive processing, I’d like to understand the methods that were used during the tests. The sections on change blindness reminded me of the old Highlife magazines I used to read as a kid and how those magazines had sections where readers were to spot differences in two given pictures. The pictures were essentially the same (a picture of a park, for example) but with several modifications to test your ability to discern subtle differences. The ten quicktime images linked in the article were very captivating to play around with; after testing them, I find it true that is difficult to spot subtle differences in pictures in a small fraction of time.
[edit] Tawan Udtamadilok 15:35, 4 March 2007 (PST)
"Perception in Visualization"
My overall impression of this article is that we have no definite knowledge of how we actually perceive things. We know that there are certain features that are easier to perceive than others in a short period of time and additonal external factors can affect that time period. I thought that the article described many great hypotheses on human visualization, and although we cannot determine why we see things the way that we do, we do know what is visually appealing to us. This helps a designer to effectively utilize visual cues to aid the user.
I enjoyed the fact that this article had many visual aids to explain some of the concepts. The exercises were very effective, my favorite being the quicktime movies where the user is supposed to find the difference between two images when there is a pause in between the two. I have never thought about the significance of a break between two images, and it is something that should be taken into careful consideration in interfaces.
[edit] Brian Loo 16:17, 4 March 2007 (PST)
“Perception in Visualization”
This article describes the concept of preattentive processing and shows through several examples of preattentive visual features such as target detection, boundary detection, region tracking and counting and estimation. It then proceeds in discussing 4 main theories behind preattentive processing which are feature integration, texton, similarity, and guided search. Feature integration measured time and accuracy for determining a target among several distractors. This theory was able to find a relationship between differentiation of target and distractors impacted the overall search time required. The texton theory was aimed at the impact of different texture patterns such as crossing segments, elongated blobs, or ends of line segments. This theory reminded me of the 3-D eyes test that one takes during an eye exam where you have to spot the pattern difference. The similarity theory built on top of the previous two with addition of search time is impacted based on the number of targets needed to be found and how easy it is to locate them. Finally, the guided search theory is the idea that the target is found through a guided search and a directional map that goes from top to down or bottom to up. The remainder of the article discusses about the ideas of post attentive processing, feature hierarchy, change blindness, and how visual appeal affects our visualization. Post attentive is the concept of one’s long term memory that examines what happens after we stop paying attention to one thing and look at another object. The most interesting section I thought was the change in blindness, which is the idea that of “an interruption in what is being seen surrenders us blind to significant changes.” I truly enjoyed this reading. I would say this was the best reading so far for this class as it provided several easy to follow examples to compliment the explanations. In addition, the reading also had an interactive component, which made the concepts even more understanding as I could interact and now remember them by an experience. This reading reminded me of the famous example of watching basketball players passing a ball and counting the number of passes. Once you focus on one thing, you do not pay attention to anything else. As a result, in the middle of the players a gorilla walks through the middle and many people did not even realize it. This article is a good example on why understanding the visual process is crucial to designing as it impacts users greatly and can make the design a good one or bad one.
[edit] Esha Datta 22:15, 4 March 2007 (PST)
"Perception in Visualization"
I found this article very interesting, especially all of the interesting visual examples which allowed the reader to test out the principles discussed in the paper. I think that it would be very important to take into account this information about how people see images when designing user interfaces. User interfaces must be able to be correctly interpreted without much thought. In many cases, there may be a time constraint when the user feels the need to complete the task as fast as possible, such as at an airplane check in station or a ticket machine. At these times, users are in the preattention phase and must interpret visual cues of information based on first glances and impressions. From this article, it is clear that color may be the primary tool in guiding users to find the correct information. For example, most people associate stop signs with the color red as opposed to the octagon shape. The color is the main clue for finding this target and the shape provides a helpful secondary clue. Varying shape and movement also seems to be helpful. When highlighting one important feature, it would be helpful to make sure that it is substantially different and that other less important features which may be distractors are similar to each other.
[edit] Anar Joshi 22:54, 4 March 2007 (PST)
“Perception in Visualization”: The article began with a general introduction to preattentive processing, which is the detection of visual properties preceding focused attention. There are four basic theories of how preattentive processing occurs which include, feature integration, texton theory, similarity theory, and guided search theory. There was also a discussion about change blindness, which is where viewers are blind to significant changes in an image. This means that a certain image can be distorted by the viewer’s internal forces such as their expectations or moods. There are many explanations suggested to cause change blindness such as images being overwritten, not storing images, or images being stored, but not compared. After reading the experiment that tested the theory about images being stored, but not accessed, I realized that there are many times that I am unconsciously aware of something, and do not realize it until I am specifically asked to recall it. I think this article will be really helpful in understanding how to design things keeping in mind the user’s visual interaction with the product.
[edit] Monica Tanza 01:02, 5 March 2007 (PST)
Perception in Visualization
This article discussed how people perceive things, especially when just using their low level seeing, which basically just means what you see in a group of objects at first glance. I think this is an important thing to consider in design because certain combinations of colors and shapes make it easier for people to be able to distinguish the target. When designing, you want to know these combinations so that you can easily direct users to a certain target button. It would be interesting to read more about this application of perception in visualization in design. I liked reading this article because there were a lot of examples so you could get easy proof that confirmed what they were saying. The most interesting part was change blindness, which proposes how hard it is for people to distinguish changes between pictures if there is a blank screen flashed in between images. It was really hard to detect the changes! What was also interesting to note is that once I noticed the change, it was really obvious, but if my attention was not on the correct part of the picture, it was impossible to notice
[edit] Rakesh Vij 02:17, 5 March 2007 (PST)
Perception in Visualization: The reasoning behind this topic is that since human perception plays an important role in the area of visualization it is important to understand perception in order to better display messages/information. The concept has been discussed and studied various times by other scientific organizations as well, solidifying the topics importance. The reading then discusses preattentive processing, which are basically things that our eyes are used to so they can recognize them faster. Anything that takes between 200-250 milliseconds is considered preattentive. The reading is cool in the sense that it has interactive programs. Namely, the Java program which shows you different colors, shapes, and conjoins the two showing you how preattentive recognition goes. Next the reading describes four tasks that follow preattentive detection, they are: target detection, boundary detection, region tracking, and counting/estimation. Next four theories explaining preattentive detection are explained. The reading then gets into change blindness and how blindness occurs in our low-level visual system. The reading then describes other features of vision such as lack of storage, color, and texture. Overall this reading was quite informative, and was very enjoyable due to its interactive nature.
[edit] Michael Chen 07:20, 5 March 2007 (PST)
Perception in Visualization: As the first article with interactive elements, it definitely stood out. The animated pictures were well used, though the Java applets contributed only marginally to the paper. Yes, it did illustrate the point, but the point was already well made in the paper. On the other hand, the change blindness tests, when viewed as a game, was really really difficult. I spent quite a long time and chanced against epilectic seizure trying to figure out the difference is in the gift wrapped stack of $20 bills, and I still can't figure out what's changed. Same thing for the airplane. One thing that was particularly useful, from a practical point of view, was the concept of post-processing, and how prolongeed exposure to a pattern contributed very little to the feature set. This means that the design has to be perfect up front, because familiarizing yourself with the interface will not help out with search-and-locate times.
[edit] Ricky Surachman 09:49, 5 March 2007 (PST)
"Perception in Visualization"
This is one of the most interesting article that i have read for this class. This article discuss about how human's visual works and hopefully the designers can understand and apply it to their design. One of the most interesting part about this article is the interactive part. The "Preattentive Process", where the readers try to detect whether there is a stood out symbol, and "Feature Hirearchy" interactive, where the readers try to recognize boundary are both interesting, but the one that amaze me is the "Change Blindness". In "Change Blindness", the readers are trying to find the difference between two frame that kept being repeated. It really intersting because sometimes eventhough the difference is really obvious, like the change of pants' color in "market" and the change of fence's height in "dinner", it took some time for the readers to recognize these differences.
[edit] Katherine Tong 10:44, 5 March 2007 (PST)
"Perception in Visualization"
I really enjoyed this article because the visual images throughout the reading really helped me understand the concepts being described. The explaination of different preattentive processing was especially interesting. The thorough descriptions of shape, size, hue, and motion really gave me a deeper understanding of how my visual thought process works. I also found the change blindness section particularly interesting because there are many times when I notice something different in a scene but cannot recall what it is. The four main components of change blindness are overwriting, first impression, nothing is stored, and everthing stored/nothing compared and every person deals with change blindness in a slightly different combination of these. After having read this article, I think I will actively try to increase my understanding of why I enjoy looking at certain visual features than others.
[edit] Connie Ko 11:03, 5 March 2007 (PST)
"Perception in Visualization"
Perception in Visualization talks about preattentive processing through four different theories: feature integration theory, texton theory, similarity theory, and guided search theory. I found texton theory and similarity theory to be most interesting mainly because it is easily understood through common sense, the other two theories take little more processing before it is understood. I also enjoyed the section on postattentive vision where Jeremy Wolfe suggests that previewing a scene doesn't necessarily mean that the viewer will find the target faster. The next topic, change blindness, is also very interesting. There are many theories on how people are "blind" to certain parts of images but the general idea is that certain features in an image are recognized without focused attention while other features are not. I like the hypothesis that "Everything is Stored, Nothing is Compared" compared to "Nothing is Stored" because it makes more sense to me that sometimes you just need a visual reminder to check something. It also explains why some people remember more details off something than another person. It seems that although there are a lot of theories on how humans perceive and process images, there still isn't a definite answer.
[edit] Christopher Ling 11:08, 5 March 2007 (PST)
“Perception in Visualization”
This article discussed some of the features of how we visualize objects. More specifically, it overviewed the theory of preattentive processing, which is the “limited set of visual properties that is detected very rapidly and accurately by the low-level visual system”. I have never read a study that discussed this theory or even thought about what my reaction time was to be able to distinguish a unique target from a set of random or homogenous distracters. I enjoyed trying the series of tests, such as the applet that allowed you to increase or decrease the display time. My accuracy and response time actually did decrease when I set the applet to run under 200ms. The article then discussed supporting theories to the preattentive process, such as Feature Integration Theory, Texton Theory, and Similarity Theory. The concept of the feature map was interesting in the Feature Integration theory because it gave me a more spatial representation of how to picture the way our mind perceives things. I felt the theories that came after the original theory by Anne Treisman were all expansions to provide more detail, such as the Texton Theory, which defined our detection of groups of features called textons. Another theory that interested me was the Guided Search Theory because it provided another means to visualize the interrelationships between feature maps using bottom-up and top-down activation. Overall, I felt this article was extremely interesting because I had never learned or read an article about this topic.
[edit] Bryan Boling 11:40, 5 March 2007 (PST)
“Perception in Visualization”
I found this article to be a very interesting read. I’ve never really thought about how I process images I see everyday, and I didn’t realize that there were multiple levels of processing occurring during normal vision. By providing images and short quicktime clips, the author of this article allows the reader to understand the physical meaning of the ideas presented in this paper. When you look briefly at an image of red and blue circles you can immediately, or “preattentively” as the article suggests, identify the boundary between differing hues. Also, this was the first time I was introduced to the idea of “blind change”, but after viewing the 10 or so quicktime clips provided in the article, I’m quite aware of what it means. I never realized that I could just ignore such significant changes in the image I see, and it makes me wonder how much of what I see everyday is based on what I expect to see and not what is happening. So overall, this was an interesting article to begin our discussion of visual perception.
[edit] Andrew prasetyo 11:49, 5 March 2007 (PST)
“Perception in Visualization”
This article is an interesting article about human visualization. I am amazed to read how human visual perception works and how it can be utilized for design purposes. The most interesting part of the article is the Research Blindness section. This part explains how our visual perception can be tricked even though there is an obvious change in the picture. Each sample picture requires careful examination before one can actually identify the differences. I also agree with the author that human perception can identify changes in the environment based on color, texture, and motion. Knowing these three visual changes is very important, especially for a product designer because a designer should be able to design a product that utilizes these three aspects of human visual perception. A good design has a “catchy” color and texture, but can still attract customers. Often times a successful product design, with the right combination of color and texture, can attract the customers’ attention only after a few exposures.
[edit] Christine Shih 12:34, 5 March 2007 (PST)
"Perception in Visualization"
This article was kinda interesting. It talks about the importance of human perception in visualization. Preattentive processing refers to the what you see before you actively focus your attention- like low-level visualization. You should be able to perform preattentive tasks in less than 200 to 250 milliseconds. The article talked about 4 different theories which described how preattentive processing occurs: feature integration theory, texton theory, similarity theory, and guided search theory. I thought the change blindness portion was particularily interesting because it seems that it shouldn't occur.. i thought it weird in the tv actor ex: that people didn't notice that the main character had been switched. The explanations for the phenomena were interesting as well: first impression( you only remember your initial impression), nothing is stored (you don't remember after you stop watching- so like short term memory), and everything is stored and nothing is compared.
[edit] Joshua Funamura 12:46, 5 March 2007 (PST)
"Perception in Visualization"
This was an interesting article about the different mechanisms by which we 'notice' things. It seemed important, in terms of information presentation design, to try to allow as much information as possible to be processed preattentively, without causing interference. I thought the change blindness section was interesting, as the principle has been applied to operating systems already, like in Windows where an outline of a window will shrink down to the taskbar, or the similar genie-effect in OSX. The gradual change, along with the movement, allow us to notice the difference and understand that a window is being minimized. Within the change blindness section, I particularly liked the "everything is stored, nothing is compared" hypothesis, where the test subjects could remember details, but only when their memory was jogged. I thought the experiments were quite inventive, and reminded me of social psychology experiments with the same goal of revealing patterns of behavior without the subject knowing. Overall, it seems that the principles explained in this article would be helpful in designing interfaces in subtle ways, with the potential to make a big difference in usability.
[edit] Patricia Wang 12:57, 5 March 2007 (PST)
"Perception in Visualization"
This article describes the effect of human perception on the analyses of images, which ultimately plays a weighty role in one’s interaction with any design. It first overviews preattentive processing and the four theories describing how such a phenomenon occurs. The first of these theories, feature integration theory, was developed by Anne Treisman, one of the first to explore the area of preattentive processing. In addition to her extensive documentation of what visual features induced preattentive processing, Treisman proposed a framework for how preattentive processing occurs, which was essentially based on a dichotomy of serial and parallel search modes represented by a sort of mapping system. I most enjoyed the last part of the article that discussed how color, texture, motion and nonphotorealism are used in visualization. It was interesting to see how these common perceptual properties could be broken down into distinct metrics that if adjusted, would change the effect of the property on visualization. For example, the article mentions a combination of statistical analysis and experimental study resulted in a distinct list of texture dimensions like regularity, directionality, contrast, size, and courseness.
[edit] Yang Hung 13:40, 5 March 2007 (PST)
"Perception in Visualization"
The article first talks about preattentive process, which is "the ability of the low-level human visual system to rapidly identify certain basic visual properties." I really liked the interactive java applet that let me test if I can retain information at a 200-250 millesecond scale. Next the article talks about the theories of preattentive processing, which include feature integration theory, texton theory, similarity theory, and guided search theory. The reading closes with discussion on change blindness, which is when an interruption between images renders a user "blind" to changes that occurred between the images. I found this part of the article to be most fascinating. I really liked this reading because of the interactive pictures and applets that accompanied the text explanations. After reading this article, I have a lot of good ideas to improve upon the product for the final project.
[edit] Megan Whittey 12:58, 5 March 2007 (PST)
"Perception in Visualization"
This article was interesting to read but a little too long. I did enjoy some parts of the article alot though. I liked how it gave many picture examples, so you yourself as a reader could see examples of the experiments and try them out yourselves. They also had interactive models where you could set up the experiment on yourself and try it and see if you were correct or not. This was mostly for the preattentive visual processing part, which was also a very interesting read with the examples it provided. The article also discussed 4 different theories that helped explain more about the preattentive processing, which were feature integration theory, texton theory, similarity theory, and guided search theory. These helped my understanding even more of the preattentive processing. Another part that I enjoyed reading was the blindness portion about how people don't notice or realize when something has changed in a scene and then they explained different reasoning behind it. I found it hard to believe but once I did a couple of the experiments with the pictures and quicktime videos I realized how easily it occured. I also found it comical that when people were watching a movie they didn't even realize when the main actor switched to a completely different actor. And I found it interesting when a majority of people didn't notice when the basketball went missing from the guys hands that was asking for direction, but once asked about it they were able to recall the basketball and even exactly what it looked like. Overall, it was an interesting article and I especially liked the interactive parts.
[edit] Marshall Anderson 13:22, 5 March 2007 (PST)
“Perception in Visualization”
I throughly enjoyed this article because it seemed to give a complete overview of past and recent research into visual perception. I was particularly interested in the article because it addresses several questions that I had developed one my own. In particular, I have been interested in how details in your vision but outside of your focus are stored if at all in your memory. My interest came from a show that said that we as humans are only actively aware a small percentage of what we actually see. This idea would then give support to the “Everything is Stored, Noting is Compared” idea of Change Blindness. I found the whole part on pre-attentive processing very interesting as well but I really wanted to see some research in pre-attentive processing of words and letters. When you quickly glance at a word do we pre-attentively know the word or just what it looks like? I got a chain letter once that illustrated the fact that you can read quite accurately even if the letters that make up the words, expect for the first and last, are scrambled. This seems to indicate that we pre-attentively process words based on how the words look. Pre-attentive processing of unique details does not rely on your long term memory, but processing of words by pattern must....interesting.
[edit] Sumeet Patel 13:24, 5 March 2007 (PST)
"Visual Perception and Visualization Technique"
This article was really interesting and kept me involved with all the pictures and was a welcome change to previous articles. The article discussed preattentive processing which consists of feature integration theory, texton theory, similarity theory, and guided search theory. I liked how the visual images in the article were testing your response rate to finding certain things. It reminded me of the Where’s Waldo books, where there are a million different people and objects in a picture and you have to find Waldo in them. I thought the example with the television main actor was interesting because no one really noticed the change. I know in shows that go on for years like soap opera’s, actors for a certain character are changed frequently and viewers don’t mind. Overall, I thought this article was interesting because it shed some light on how we perceive things.
[edit] HAK-SEUNG KIM 13:42, 5 March 2007 (PST)
"Perception in Visualization"
This article tells us very interesting topic, visualization. There are five senses such as sight, hearing, smell, touch, and taste. People buy and use the product with these five senses. The author, especially, demonstrates on the importance of sight in this article, visualization. What is our first experience of the objective? Smell? Touch? I think that seeing is the first thing most people do, so that they can smell, touch, taste, and hearing. With the preattentive processing, human visual system analyses the image or objective. Also, the author shows that the visualization is used in many different jobs such as army, advertising industry, tourism, etc. Overall, I enjoyed reading this useful article.
[edit] Richard Chen 15:07, 5 March 2007 (PST)
"Visual Perception and Visualization Technique”
One thing that really resonated with me after reading this article was that there are so many different ways in which we perceive things, and yet, we still have no concrete theory that explains human perception. Overall, I believe that this atticle is a must-read for people who are involved in print advertising, where the layout and the visual medium are integral parts of a successful (or not so successful) advertisement. By studying the current hypotheses on how humans perceive, we can definitely leverage that knowledge in selling a successful product. Thus, these theories on human perception would not only be of great use to advertisers, but also designers whose jobs are to always keep their end users in mind. Being able to “see through” the eyes of their users, the designer would be much more capable of creating products that would be easy and intuitive to use. Furthermore, the many visual exercises that were part of this article were very enjoyable in that they reminded me of the experiments that I had partcipated in a psychology class. These exercises truly show that there are certain cognetics that are associated with visualization and perception—and that ignoring these principles would definitely be a shortcoming in creating a potential product on behalf of the designer. Also important was the discussion of how color was a huge factor on how to obtain the user’s attention, and it goes to show that the designer has to make certain trade-offs on the colors to use to grab their attention, while not sabotaging or reducing the presence of other features or signs. Finally, I think this article truly drove home the point that design is truly a very inter-disciplinary art as well as science, encompassing a multitude of disciplines such as psychology, cognitive science, among so many others.
[edit] Raymond Kim 13:57, 5 March 2007 (PST)
This article was a very interesting read that discussed the concept of preattentive processing, which explains how the brain perceives visual stimulation and processes images. Several theories were presented by the author such as integration theory and similarity theory. It has always interested me to discover more about our subconscious or routine actions such as the simple act of taking in your surroundings. Many great examples were presented in the article along with pictures which made for a much more interesting read. The example of the "changing actors" was particularly interesting and goes to show just how much the brain can miss while processing images. The application of visual research into modern product design is also widespread, from the design of computer interfaces to a simple color scheme for a banner. Understanding how the human mind perceives images is the first step toward creating products that are visually noticeable.
[edit] Asmita Karandikar 14:04, 5 March 2007 (PST)
"Perception in Visualization"
The goal of this article is for the reader to gain a better understanding of how perception works, with the intent to improve the quality and quantity of information being displayed. The article focuses on four main topics - preattentive processing, postattentive processing, change blindness, and perception in visualization. Preattentive processing is the idea that humans have the ability to quickly detect and identify certain basic visual properties, and deals with these properties that will focus one’s attention on that object in the scene. Postattentive processing is the theory that knowledge gained through previous exposure to a scene will not help one learn more about the scene. Change blindness is the idea that an interruption in viewing a scene makes us unaware of significant differences between the scenes. Perception visualization gives examples of how perceptual properties such as color, texture motion, and nonphotorealism are used in visualization. I found the section describing preattentive processing to be very interesting, and I’m curious to know how much these theories are applied in the advertising sector, where companies are trying to attract customers with their ads. The section on change blindness reminded me of puzzles where the reader is told to find a certain number of differences between two scenes that would otherwise have been identical. Overall, this was one of my favorite articles of the semester, as it was very interesting to read.
[edit] Erin Palermo 14:09, 5 March 2007 (PST)
Perception in Visualization
I thought this article was both interesting and fun! All of the visual "games" were fun to try, and interesting to see the results. These theories are important, because the way that humans perceive images is imperative to understand when designing. It talked about 4 different theories about the preattentive process: feature integration theory, texton theory, similarity theory, and guided search theory. Further, I enjoyed reading about "change blindness," along with trying the tests that were presented. I got frustrated when I couldn't spot the changes quickly! I shared the tests with my roommate, and she was very quick at spotting the changes, which made me feel like I should be better at it, but change blindness is a phenomenon that humans can't control. I didn't like that there exist features that cannot be detected, even when viewers actively search for these exact features. Once the change is apparent, then it seemed so obvious that there was a change between the pictures, but it was so tricky at first. Human perception is very cool, and as designers, we have to take advantage of these techniques and theories in order to design an effective product.
[edit] Michael Lovejoy 14:30, 5 March 2007 (PST)
“Perception in Visualization”
I thought this was a very interesting concept for an article. I especially liked how it focused on preattentive processing. I learned those concepts previously in a basic psychology course, and I find it amazing how we can tell if something is preattentive based on how fast our eyes can focus. Preattentive processing is more the parts of a display that catch our unconscious attention, so it is very important and also somewhat difficult to take into account. I didn’t really like how the article seemed to trail off into unimportant details of the theories behind the ideas. However, the theories presented were quite intriguing, and would have been nothing without all the pictures to help us along. Since image processing in general is such an important idea with so many applications, I would have liked the article better if it gave some applications of these ideas to things like advertising. Something like that would have made the ideas more concrete and valuable.
[edit] Umber Masood 14:37, 5 March 2007 (PST)
“Perception in Visualization”
This article was an interesting read. The conclusions reached in the article can be used to improve visual design. This article is different from previous readings, which have focused on testing, building prototypes, or interviewing users. The article gives good guidelines for how to design something when information needs to be communicated or attention needs to be drawn to a specific detail. The subject of the article is very useful, and it can be applied when designing a website, user interface, flier, or logo. One example of visual design is the FedEx logo. The arrow in the logo implies speed in delivering packages. The logo has won design awards and is a good example of an image telling the goals of a company. While Healey’s article is very well written, it only addresses users who are able to use their sense of sight. It does not tell how visual messages can be relayed to users with visual impairments or those who are color blind. For this latter group of users, alternative methods need to be found to meet their needs.
[edit] James ChunJye Tong 14:39, 5 March 2007 (PST)
"Perception in Visualization"
I think this article is interesting to read. It provides many examples to help the readers understand the terminology about how we see things. It explains preattentive processing, it explains how human eyes analysis images. The four theories that explains preattentive processing are feature integration theory, texton theory, similarity theory, and guided search theory. I thought the part about postattentive vision system is interesting. I was surprised that the result of postatentive search was lower than the traditional search. I always thought it might be easier to be able to find the target image if the person can see the images ahead of time. Some of concepts that the article might seem to be obvious and I think it is very interesting to understand how people react and analysis these pictures.
[edit] Michael Toulouse 14:42, 5 March 2007 (PST)
"Perception in Visualization"
The article is mainly about how people visually sort things rapidly on a low level, which it calls preattentive processing. It could include size, shape or color, and shows several examples. It then covers several theories about how the sorting happens. However there are four theories, and much seems to be taken from experiments with somewhat limited import. Each theory had its fair share of exceptions. The animated GIFs were interesting though. The dollar bill required a good amount of time. For the most part, although generally an empirically gathered conglomeration of small deductions (we dont store things, colors stand out, etc.), the article did provide good input into the current state of perception study.
[edit] Urvashi 14:44, 5 March 2007 (PST)
"Perception in Visualization"
This article was fun to read as I got to experience first hand what the author was trying to explain with the help of the various diagrams and the applet. The visual games made it apparent how some processes are pre emptive and some are not. It also did a good job of explaining the several theories that were feature integration theory, texton theory, similarity theory and guided search theory. The article also compared two different search methods, the traditional search and the post attentive search and found that the postattentive search was slower than the traditional one. The result of this study had a very significant impact on visualization design and hence using methods that quickly draw viewer's attention to a particular thing were found to be a much more effective way of communication what needs to be sent across to the viewers as it will get their focused attention. Change blindness has also been discussed, with several pictures given as examples. Five explanations have been offered for this, and they are first impression, nothing being stored, everything being stored, overwriting and feature combination.
[edit] Justin Hsu 14:58, 5 March 2007 (PST)
"Visual Perception and Visualization Technique"
The article "Visual Perception and Visualization Technique" was an interesting read that summarized some of the existing theories in visual perception. I like this article because it was very different in nature than than our previous readings. I can see why visualization concepts are extremely important when it comes to design. A designer should understand these principles so that he or she can better cater elements in his or her design to have a given desired effect (i.e. distinguishing between one element from the other, focusing in on a single element). The concept of preemptive recognition was an interesting one. It made me think of how it can and should be applied to our current project's theme of persuasive design. It illustrated many different ways to appeal to a user's sense of distinction. In a persuasive design, the good habit that the product encourages should be be recognized without any effort and by second nature intuition. A variety of design themes can be exploited with the knowledge of which preemptive elements can be incorporated within ones design. What I enjoyed most about this article was the fact that it had interactive programs and pictures to illustrate each and every concept that it introduced. Reading about several theories of visual perception in black and white text is one thing; but actually seeing and experiencing the phenomena is another. Having the illustrations/movies/programs made it much easier to absorb what exactly the author was talking about. In particular, the diagrams with the red/blue square/circles very effectively illustrated the limitations of human visualization depending on several parameters (i.e. exposure, number of elements in the display, color, shape, etc.) The change blindness concept was also very well illustrated with the 10 variation frames provided. This aspect of the article made it very fun to read and learn. An extremely popular electronic game frequently found in bars called PhotoHunt is based on the concept of change blindness. I thought this to be interesting because it is an instance from my own personal experience where a visualization concept is used for commercial means.
[edit] ChuiShan Wong 15:01, 5 March 2007 (PST)
“Perception in Visualization” After reading the article “Perception in Visualization” by Christopher G. Healey, I found that human perception in visualization is very important. According to the reading, there are four different theories in the preattentive process. They are feature integration theory, texton theory, similarity theory, and guided search theory. I was surprised when I was reading the part that color, texture, motion are techniques that frequently used in visualization. The author says that adjusting those would bring a great effect on visualization. This is a very good point because I usually focus on the main design and neglect those minor things.
[edit] YeeWan Cheung 15:10, 5 March 2007 (PST)
Human eyes are amazing. With this low-level visual system, we can detect a limited set of visual properties very rapidly and accurately. The author starts out by introducing these properties which are called preattentive, since their detection seemed to precede focused attention. The author uses examples to demonstrate our visual system's way of identifying the target through a difference in hue or curvature or a combination of the two.
The author then brought in four models that explain how preattentive processing occurs within the visual system are the feature integration theory, texton theory, similarity theory, and guided search theory. I found the texton theory being the most interesting one because even given two objects that look very different in isolation, they can still be consider as the same texton. The example that was given in the text is two blobs with the same height and width, but each is very different from the other. I was amazed that this texton is given me such a hard time to distinguish between the two.
In the later section, the author discusses those new research discovery, which came to the conclusion that there are only certain features in an image are recognized without the need for focused attention, and that other features cannot be detected, even when viewers actively search for these exact features. I found the idea of the change blindness very interesting. after i have saw a couple movie clips, i still couldn't notice the changes within the movie. This is cool. haha! It makes me feel better when i saw the author wrote"change blindness is not a failure to see because of limited visual acuity; rather, it is a failure based on inappropriate attentional guidance".
[edit] Shwan Kazzaz 15:19, 5 March 2007 (PST)
This article is very interesting as it addresses one of the most intersting and most ignored aspects of design. The layman user often takes for granted how easy visual cues make a task. For example, green means go, and red means stop, but what if we the lights were all green? And the top light meant go, and the bottom light meant stop, but green and red were still proceed and halt conventions in everyday life? The importance of understanding how a user operates is greatly important, and this is especially true in dealing with vision. Visual perception is a users first and immediate sense to take in a cue from an interface, and this can often affect how the subconscious reacts. I particularly liked a sentence in the article that described the difficulty of discerning patterns from distractors. This can be true anywhere, and is important specifically in the dashboard of my car, where too many buttons clutter the small area.
[edit] Shilpi Verma 15:31, 5 March 2007 (PST)
“Perception in Visualization”
The article first starts out with discussing preattentive processing, “the ability of the low-level human visual system to rapidly identify certain basic visual properties.” The visual examples depicting preattentive processing were really helpful because they demonstrate specifically how preattentive processing works in our brains. The article then went on to discuss the four theories of preattentive processing: feature integration theory, texton theory, similarity theory, and guided search theory. The feature integration theory is based on response time and accuracy. Treisman performed extensive studies to extend feature integration to explain cases where conjunction search is preattentive. The texton theory focuses more on statistical analysis of texture patterns. Julesz describes textons to be classified into three general categories: elongated blobs, terminators, and crossings of line segments. The similarity theory investigated conjunction searches by focusing on two factors related to search time: number of items of information required to identify the target and how easily a target can be differentiated from its distractors. The guided search theory by Wolfe explains traditional “parallel” visual search. Targets are found through a guided search and a directional map, which can go from top down or bottom up. The reading then goes in and talks about change blindness. I found it interesting that blindness occurs in our low-level visual system. Overall, I thought this reading was pretty informative. It was definitely really long, but the material was somewhat interesting.
[edit] Minhaaj Khan 15:53, 5 March 2007 (PST)
Perception in Visualization
This article covered a lot of concepts but was very interesting and had a lot of visual examples to explain concepts. The author began by talking about preattentive processing; "a limited set of visual properties that are detected very rapidly and accurately by the low-level visual system to identify basic visual properties…their detection seemed to precede focused attention." As I read this I thought about “Where’s Waldo?” and how it relates to the reading as it is difficult to find Waldo in a lot of pictures because preattentive processing is suppressed by visual interference. It was fun to try out some of the visual tests/examples provided to reinforce the textual explanations which was a little dense.
There were four theories on preattentive processing the author cited which talked about how preattentive processing occurs with our vision. These theories were the feature integration theory, texton theory, and similarity theory, and guided search theory. All of these theories made sense at some level, but the most intuitive and possible the easiest to understand was the similarity theory. It makes sense that target and non-target relationships coupled with non-target to other non-target relationships are very important in determining efficiency and search times. The author explains that, “T-N similarity is the amount of similarity between the targets and nontargets. N-N similarity is the amount of similarity within the nontargets themselves,” and intuitively if T-N similarity decreases and N-N similarity increases you can assume without testing that preattentive processing will apply to the visual.
The section on change blindness and the four theories behind it were really interesting. Some parts of the eye and the brain are clearly responding differently to the two-picture examples that were on the website. The explanations on change blindness (overwriting, first impression, nothing is stored, everything is stored/nothing is compared, feature combination) were very interesting and got me to wondering what the right answer for the cause of change blindness actually is.
Lastly, I found the authors claim that studying a display may not offer assistance in searching for specific visual data values. Although some might argue otherwise, I always think about the comics section in the newspaper where they have two very similar looking pictures right next to each other and you have to find all the differences between the two. Sometimes it is difficult to find all of them even when both pictures are right there to look at. It seems that as you focus your attention from one picture to the other the whole concept of change blindness comes into play and without dividing the pictures up piece by piece and paying attention to detail it becomes impossible to know the difference even if we have knowledge of what it is we’re looking for (i.e. studying the previous display to find differences).
[edit] Ryan Jue 15:54, 5 March 2007 (PST)
Perception in Visualization
This article was about how we perceive different visualizations and how we can pin-point abnormal aspects through different methods like shape and hue. I thought that this article was very interesting and especially like the java applets that were embedded in the html document. These applets I thought really brought the ideas to life with the ability to change settings to identify the target if it was present in the mix. Using different types of visualizations to demonstrate represent different types of data is really effective and from the examples in the article, I realized how common these usages were from map graphing to the weather forecast daily on tv.
[edit] Hong How Quek 16:03, 5 March 2007 (PST)
Perception in Visualization
The article discusses various theories of human perception that have been established in the last two decades, such as preattentive processing and postattentive vision. Although the descriptions are rather technical in nature, it is still possible for the layperson to grasp key ideas presented, as few complex jargons are used and when they are, the author makes sure they are well-defined. Preattentive vision as the name implies refers to task that precede focussed vision, thypically taking less than 200-250 ms on large multi-element displays. I found the similarity theory (T-N similarity and N-N similarity) to be a reliable and easily understandable tool that can be used to predict the success of preaattentive vision. To extend the theory to real-life, N-N similarity is also the reason why an unsually tall person or an exceptionally beautiful person sticks out of the crowd. However, the correlation between T-N similarity and N-N similarity is not so clearly described. I found the feature hierarchy section to be very interesting too, that we process color differences much more quickly and easily than shape differences. Perhaps the brain is wired to notice color differences from birth, but we have to actually learn to recognize shapes and their differences. The gap between what is a reflex action and what is a learnt action may account for the difference in visual recognition speeds between colors and shapes.
[edit] Aubuchon 16:03, 5 March 2007 (PST)
“Perception in Visualization”
This article discusses the importance of understanding human visual perception in design. First, there is the notion of “preattentive processing.” This is essentially the first pass that the human brain makes at recognizing a visual image. The brain provides the user with a rapid notion of what the visual picture is, without becoming focused on a particular item yet. The article then discusses four theories of how the brain tends to recognize visuals on this low-level of preattentive processing. Feature Hierarchy is another important characteristic of human vision. For instance, a blue square may be perceived first as either being a square or as being blue. Feature hierarchy is the study of what the human brain will favor to interpret first. All this theory is useful insofar as it helps to apply it towards actual design decisions. Such decisions come into play as color, motion, and texture. For instance green has the convention of “go” and horizontal lines always make me look fat.
[edit] Royapakzad 16:28, 5 March 2007 (PST)
“Perception in Visualization”
This article was very interesting since it focused on the importance of perception of visualization and how we can differentiate and distinguish between different components of an image in a certain amount of time. The similarity theory proposed by Quinlan and Humphreys was very interesting. After looking at the images in the article, I realized that the relationship between T-N similarity and N-N similarity was exactly the same as what Quinlan and Humphrey suggested. Moreover, the theory that I agreed with the most was Jeremy Wolf’s theory and that is: “early vision divides an image into individual feature maps….for example in the color map there might be independent representation for red, green, blue, and yellow.” When I looked at the images, I would first separate the red color components from the blue ones and then distinguish between the ones that were vertical versus the ones that were sloped. I think overall understanding human perception of visualization will help designers how to make images and maps more understandable for viewers.
[edit] Rabia Siddiqi 16:34, 5 March 2007 (PST)
Perception in Visualization
This article was about how human perception and the importance of its consideration in design. Most of it was very interesting, but at times it became too technical. However, the pictures were very useful in clarifying what the article was saying. The most important concept was “preattentive processing” which is the initial recognition of an image after about 250 ms of looking at it. There are some things that stand out during this processing and others that go unnoticed. I found it fascinating that color variation can distract the mind so that simple form recognition cannot be initially detected. I also liked the flickering images in which the picture changes significantly from frame to frame, but we generally cannot perceive the change. Even after watching them carefully, I was only able to recognize a few of the changes. This article is useful for designers because it is very important for them to consider how their users will interact visually with their products.
[edit] Jason Hu 16:38, 5 March 2007 (PST)
This broad yet fairly detailed overview of human visual perception was interesting in many ways. Since it was somewhat densely written, I appreciated the multimedia examples provided throughout the article. One of the most significant messages I took away was Wolf’s conclusion that “sustained attention to the objects tested in his experiments did not make visual search more efficient.” In terms of design, this means that preattentive methods must be used to design visual displays that are quickly and easily readable since their contents will not be reliably committed to long-term memory. I also found the analysis of change blindness to be interesting. If our visual systems are not like film photography, which faithfully replicates images to memory, but rather more like a video, which continuously reconstructs the same image line-by-line, then we must design our visual interfaces to easily direct our users’ attention according to that phenomenon.
[edit] Ryan Panchadsaram 16:41, 5 March 2007 (PST)
Perception in Visualization
I enjoyed this reading, especially for its value in our GPS saftey project. When we design our map interface it is important for us to keep in mind our users' preattentive processing. Our maps will be displaying lots of information and when an alert happens it needs to be noticed immediately. From the reading we learn that colors and shapes are a clearly identifiable way to present our information. But we must take caution and use them independently, becuase when they are mixed together identification becomes a tedious scanning task. The rest of the article covered various studies and theories on how we process images and detect differences. The portion on Change Blindness traps you for a while, but in a fun way.
[edit] Nicolas Suryono 17:10, 5 March 2007 (PST)
I think this reading is very interesting. It has some useful information on designing map interface. It also states that we need to pay attention to our user's attentive processing. Our map will aid us by displaying a lot of necessary information in our design. It also states that color and shapes are important to our design but they must be treated as an independent entities. I think this articles has a lot of useful information that will really help us in our design assignment and project.
[edit] Johannesleholm 17:09, 5 March 2007 (PST)
This was a really good article and a little different from a lot of the articles that we have read in this class. The article was also similar to the ear and hearing lecture that we heard last week. The article was also very fun and interactive; this allowed me not only to read, but to do -- and doing is the means of learning! But the interactivity wasn't the only awesomeness; understanding how many people perceive was totally edifying. The author begins by explaining pre attentive processes and how they affect our perception. The author explains how color, texture, motion, and nonphoto realism can affect the viewers perception of an image. I was fascinated how the texture could easily change my perception of a simple object. I also realize now how effective nonphoto realistic images are and how prevailant they are in our society. The goal is not only to create computerized photorealistic photos, but simply create interesting perceptions.
