Human Information Processing (Perception)
From CS160 User Interfaces Sp09
Lecture on Mar 2, 2009
Readings
- The Model Human Processor. The Psychology of Human-Computer Interaction. Chap 2. Card, Moran & Newell.
- Focus primarily on pages 24-76.
Discussion Questions
- How can the ideas presented in this chapter be applied to the design of user interfaces?
Saung Li - Feb 27, 2009 04:26:46 pm
User interfaces should be designed to take advantage of the short term Working Memory, which has a small capacity, and Long Term memory, which has a lot (almost infinite) of capacity. The user should not be bothered by interface details that are irrelevant to the task he is trying to do because the user has limited Working Memory, and if he takes his attention away from the task he may forget what he was doing. The interface should give cues to the user that help him retrieve information from his Long Term memory more easily. If the user needs to use actions that are similar to each other, those actions may interfere with what he already remembers in Long Term memory so he may have a harder time retrieving the old information. This is why interfaces designed to perform the same task should have the same commands. For example, using Microsoft Word and Emacs is difficult since they use different commands for the same tasks. The different actions interfere with each other so the user has a harder time retrieving the right data. Sometimes commands that are not used often can be forgotten by the user since the user has a relatively small Working Memory and needs reminders that allow him to retrieve information from the Long Term memory. Working Memory has a smaller decay time than Long Term memory, meaning content the user remembers in the short term is smaller than the long term. This can be helped by the use of help boxes for beginner users of the interface, and then eventually turned off when the user has practice enough to easily retrieve the commands.
Increasing the number of choices increases the Cognitive Processing time since the user has more to compare and more to decide on. The Perceptual Processing time increases as well since the user needs to read more of the choices. However, if the number of choices is grouped in a logical or meaningful way, the processing time decreases since the user can understand the content easier. For example, it is easier to remember a list of different colors when it is grouped by similarity in color than a random list of them. Practicing also decreasing the amount of Cognitive Processing since the user requires less mental steps and utilizes Motor Processing more, which moves the body. Thus, content in the interface should be grouped in logical ways so the user can understand it more quickly, and meaning labels should be used for widgets the user can better process his choices. One question I have about the reading is, what do they mean by visual and acoustic code?
Anatol Tsang - Mar 01, 2009 03:41:45 pm
I could see that human perception is related to user interfaces because understanding how humans perceive things can be used in our design of user interfaces. How we perceive things, how long they stay in our memory, and such information can be used to fine-tune our user interfaces. The information on how we remember things can influence our interface's decisions between what things to display to help our users remember things. Maybe, if we wanted to help the user speed things up, we think about allowing the user to have a look-ahead at things to cognitively process them before they have to respond to them (which may be faster).
I think all the equations and calculations are a bit over the top. The didactic language of the article makes it hard to read and understand its purpose as well.
Ling Chen - Mar 01, 2009 06:09:42 pm
Even thought this article brought up some interesting points, it was still a pain to read and to finish. Especially with all those numbers, equations, and charts, my eyes just automatically skipped over those things. That said, there were still some interesting information presented about human-computer interactions.
First thing I found interesting was that when people are asked to recall information, even just a few seconds after hearing it, they need to use both working memory and long-term memory. Never thought it would take that much work to just recall something recent. Then there's the concept of perceptual causality, which reminded me of action scenes. When you want to make a scene where A is hitting B, then you just need A to swing the fist and B to move at the correct moment. Even though A didn't actually hit B, it would look as if he was hit. It sounded almost like a common sense when the author said that the time to do a task decreases with practice. However, it still doesn't cover everything, like the acquisition of knowledge into long-term memory or the quality of performance. Quality is measured on so many different kinds of scales (percentage of errors, total number of errors, and preference ratings), and none of them has a uniform treatment.
As the article have pointed out, most user behavior is more complex than the simple decisions discussed. In order for us to understand and predict the course of human behavior, we need to analyze the tasks to discover the paths of rational behaviors. And there are two basic principles of task analysis: rationality principle, which says goals + task + operators + inputs + knowledge + process-limits -> behavior; and the problem space principle, which says different tasks have different problem spaces and the space may change over time as the user acquires more knowledge about the structure of the task.
Denise Ngai - Mar 01, 2009 08:08:39 pm
Upon reading this piece of literature, I was taken aback by the equations they used to attempt to describe human perception.
Nevertheless, taking into consideration human perception is very important when planning a user interface. A UI must be designed to cater to the needs of the human user. For example, considering how a human will process things that he/she sees or hears, a UI must be able to cater to these processes. If human perception processes certain colors or sizes of objects better, the UI should feature these colors and sizes so as to help the user be able to understand what's on the screen. Motor skills necessary for maneuvering the UI should also take into consideration human perception. The design of the UI can affect how the human user will be able to comprehend what is going on and whether or not he/she will be able to remember the controls and whatnot. For example, a huge button for "Print" is easy for the human to perceive. Each time he/she sees this button, it is easy to know what the function is for.
I felt like this reading was too long for its purpose. The reading spent so much time breaking down every little thing, explaining how certain human perception processes work when really the main point could have been summed up by the above paragraph. The whole time I kept thinking, "Cognitive Science." It is a useful reading because it does open your eyes to be aware of human needs, but it could have definitely been condensed.
Sean Hansen - Mar 01, 2009 10:36:13 pm
Although I highly doubt I'll retain many of the equations or numbers, there is a significant point that I've taken from the reading: the efficiency of an interface can be quantified. This is not to say that the time it takes for a user to perform a certain function can be predictively calculated without error, but that we have another powerful tool for improving our interface design, and anything that limits the amount of resource-consuming testing we need to do is more than welcome.
Jeffrey Patzer - Mar 01, 2009 10:57:22 pm
I think that I will have to agree with Sean here. This reading has to be one the will not long stored in my memory in regards to the charts and numbers, which there were quite a bit of. However, amidst all the information were a few gems. One was the idea that similar sounds and things crowd memory and make it harder to recall information at a later date. To me this means that interfaces should make sure actions are different to avoid confusing the user. Also, I thought the Rationality Principle was very useful. The idea that the human himself is not complicated, but the task carrying out it, which influences his behavior, is very important. This can be taken to mean that any problem can be done by a human, they just need the right tools and methods to go about solving the complicated task.
Kevin Huey - Mar 01, 2009 11:49:41 pm
Psychology class, anyone??
I think this article tries to understand the brain just a bit too much. Well, that's just saying that I believe it's way beyond us to truly understand such an organ. Regardless, it brings up a lot of interesting ideas, mostly through psychology experiments or random equations based on data from those experiments. At some point (about 2/3 into the article), it said that we as people don't truly forget, but we sometimes fail to recall certain memories. I can see the truth in this. People need certain "triggers" to remember ideas easier.
The biggest problem I have with this is the argument about chunks. I mean, what the heck? How do these experiments help at all? If people are forced to recite words right away, how would that person have enough time to remember one as a chunk and continue to listen for more words at the same time? Yes, I realize that people (myself included) do use such techniques like mnemonics, but they take either a lot of time or a lot of training to gather info that fast and use the association method for chunks. These psychology experiments, as far as I remember, do neither.
Yin-Zen "Johnny" Hwang - Mar 01, 2009 11:08:37 pm
even though a lot of the perception stuff information i've known and had to work with (especially long term memory for quiz bowl stuff), it never occurred to me to connect the human machine with UI. but that's true. in UI we try to increase efficiency by interfacing with the user, and the best way to do that is to build the hardware/software to make it more natural for humans to interface. although there's a lot of stuff that's pretty impractical/obvious/etc., there's some really practical stuff that applies: button arrangements, key placements, refresh rate, etc. and maybe when designing databases, there's also stuff we can do to make it easier for people to access data and remember data, etc.
Dwijgarg - Mar 02, 2009 01:10:46 am
This article makes a very interesting point about connecting the inner human "machine" with UI and its design. So I definitely agree with Johnny that the whole point in interface design is to make things easier for the user and to increase the efficiency of the design in a way that any human can simply understand and use the interface. Also, I like the fact that the article makes it very clear that a Model Human Processor consists of "a set of interconnected memories and processors, and a set of principles of operation." Keeping these two important points in mind, designers can effectively design a good interface that will appeal to the user with its ease of use and understanding.
Carolchen - Mar 02, 2009 01:35:02 am
First off, I laughed out loud when I read that auditory store decays slower than the visual image store, because I had the PDF of this chapter read aloud to me by Acrobat.
The example showing that more clicks per second are interpreted as one percept is a little suspect. The clicks are the same, so it is not as though they are more similar than when they are spaced further apart in time. Perhaps humans just don't have the auditory capacity to distinguish between clicks at such speeds, much like most people cannot read faster than they can sound out words in their head (though some can).
One way in which the model human processor can be applied to UI design is to consider how things are encoded and the various ways they may be retrieved, which might lead to loss of the information. This was introduced as the Encoding Specificity and Discrimination Principles. User testing can capture many of the interpretations for retrieval.
Sean Ahrens - Mar 02, 2009 01:43:42 am
I found this reading insightful, although at times a little heavy on the formulatic details of the human processing system. I have a couple comments about how the learnings in this reading can be applied to design. For one, take the fact that long term memory is a fast-read, slow-write system. This means you can't throw too many learnings at your user at once; if you do, he won't remember them all. This is because he needs time to create mental links to these short term memories with existing memories. And this takes time. A second point is that since memory is associative, it may be helpful to include a preview of things to come in navigation systems. For example, take a list of the user's health records as the screen of destination. Instead of just having a link to "Health Records", additionally showing a preview of the user's latest health record with such text as "Weight: 150lbs. Height: 5'8"", the designer can help give the user more associations to tap into as he decides whether that is the correct link to click.
Another thing I found of interest in the article is that it gives no mention to the distinction between the cognitive conscious and unconscious, as did one of our earlier readings. I am curious how this fits into the working and long term memory and the cognitive processor as discussed in this article. It seems it would be important and integral part to this "computerized" discussion of the brain, but I saw no mention.
Shoeb Omar - Mar 02, 2009 01:36:57 am
This reading was amazingly detailed and complicated. The ideas were generally interesting but I think it was a little much for our purposes in this course. Nevertheless there were some take away points, the most important of which were about the working memory. It is obvious that if we could store our entire UI in a user's working memory, it would give the impression of being extremely easy to use, as a user woul dnever have to recover information from their long-term memory. However, doing this is impossible. What needs to be worked on is storing things in short term memory and making cognitive shortcuts to long term memory for other UI components. I think images help here. Seeing button with images helps activate the relevant long-term memory before reading a button does. However, intriguing from the article was the idea that auditory information decays slower than visual information. Could this be used to advance a UI? My guess is no because UI's are visual devices. You don't hear to make them work. You could have speech recognition but, as things go, no advanced in speech recognition have been able to replace the visual idea of UI. Theoretically we could have an entire interface that runs only through talking and listening. But then you still need visual reinforcement. Perhaps I'm going on a tangent here but I think that although auditory store may last longer, visual store is more re-enforcible. If we forget what a button does we go look and recognize it again. If we forget what we just heard, do we hit a replay button? This is why we love webcast lectures--what we forget, we can go back and see again. That was a bit of a detour but my point is that cognitive shortcuts to long term memory are what would make UIs more successful. The best ways to go about this often connect to things already habituated within our minds. Although we may not always be thinking, we need to click the arrow next to a dropdown list to make a selection, seeing the arrow points us to the relevant cognitive schema for dropdowns
Cuong Ngo - Mar 02, 2009 02:32:32 am
User interface is a visual form of presenting instructions to the user to perform some given tasks. In order for the human brain to process such information efficiently, interface designers must take advantage of how it's structured. Take Long Term Memory. "When a chunk in Long Term Memory is activated, the activation spreads to related chunks and to chunks related to those." This explains why Photoshop users can quickly access the tools without having to memorize where they are. An example is the rectangular toolbar on the left side of the screen. It contains a bunch of descriptive icons, namely chunks, representing the main tools. Suppose users want to draw a line using a brush with size 4. They know that they need to click on the brush icon, which in turn activates related chunks such as shapes and density options. Therefore, the task can be performed much faster.
Mark Dhillon - Mar 02, 2009 02:39:23 am
I liked the idea of Human Information Processing being composed of processors, memories, and principles. I do agree with some of the earlier posts that this reading was a bit too in-depth for the purposes of this class. That being said, a lot of the problems and solutions presented were intuitive, and it was interesting to think about our perception of reality as a connected series of processors and memories. Ideas like when a user learns a new interface, they may have more difficulty remembering the old one drew an thought-provoking parallel between scalable data retrieval for me. This was pretty long though.
Chris Thompson - Mar 02, 2009 02:42:28 am
Ugh, this reading was a bit dense. Luckily, a fair bit of it's review for students who've taken CogSci 100 (although it's still worded pretty technically here). In a nutshell, it starts by making an analog between the human brain and a multiprocessor computer system (I believe one of the earlier readings was against using the current hot technology as a psychological metaphor as historically it's proven unsuccessful), then it goes on to see how each of the separate departments processes information. The visual and auditory stores hold brief bits of information, that hopefully will be moved into the working memory (as long as we're paying attention to the material). There's only a limited amount of room in working memory, though, so optimally you should try to encode (chunk) the information in a way that makes sense to you, because it seems like we can remember the same number of chunks regardless of how much information that can be decoded to (although the number of chunks we can remember can be expanded with practice). I don't like how they convey this information, though. It's overly scientific, as if they were trying to describe the exact equations that model the functioning of the brain. In fact, the bulk of the article isn't about the important concepts (like auditory store and chunking or how to improve upon it), but upon various response times and statistics for cognitive operations. I suppose if you want to figure out precisely how many milliseconds you have for a user to act on an input based on information that was just received, this article would be your first choice. Otherwise, I wouldn't recommend it.
Moonway Lin - Mar 02, 2009 02:45:57 am
This is a very dense and technical reading. In any case, I'm not sure that breaking down a human's response to this level of detail is necessary or useful for most UI applications. With the information presented in this article, we can now estimate the amount of time needed for an average user to perform various kinds of tasks. Most of the examples in this reading are related to keyboard design, where knowing how fast people react to certain letters is essential. (And it is rather unsurprising to learn that humans adapt to commonly seen stimuli so that frequently-appearing letters are associated with faster reaction times.) However, I just can't see common UI designs (like our task scheduler) needing such precise calculations in order to be effective and easy-to-use for everyone.
Chunwei Lai - Mar 02, 2009 03:13:21 am
Like other students, I found that the equations presented were a bit overwhelming. Some of the facts presented such as "rate at which items can be matched against working memory" were useful for considerations but most of the other facts are not as helpful in the actual design of an interface in my opinion. These type of equations/facts seems to be more important if we want a computer (AI?) to simulate a person's reaction to an interface. General observations can be made from most of these and those points highlighted should have been enough of a presentation of the idea. An interface should be designed such that the core elements can be stored in the "working memory" easily meaning the interface should be simple to comprehend and regurgitated. Perhaps in the distant future, there will be software used to evaluate an interface based on the equations/facts presented.
Timofey Titov - Mar 02, 2009 03:26:20 am
I agree that the text went into too much depth for our purposes. For me it was surprising to learn of "multiple processors" in the human brain. It makes me wonder how realistic the model is and how valid the measurements are. We can use those metrics to help us design our interfaces. It is immediately applicable in the design of tooltips, timed dialog boxes and actions. I understand now why voice interfaces have always suffered so much. People forget what they're told due to audio processing capabilities :) It is not clear how far one should go in applying this model. A problem that was touched upon is that people learn and develop habits. That is a big game changer. People remember more and react faster in such situations.
Victor Lum - Mar 02, 2009 03:48:25 am
The article gives us plenty of examples of how the whole human processor thing can be used for user interface design. Actually, it probably went into a little too much detail, giving us equations for every little thing from perception ability to reaction time. But basically, the point that I got from the article is that there is a way a measure how well your user interface is, beyond just asking people whether they liked it. It seems like if you do lots of math, you can come up with some number for how well your user interface is working for the different speeds of humans.
Matthew Can - Mar 02, 2009 03:30:38 am
This reading was a nice refresher of some material I learned in a psychology class. Some of the perceptual and cognitive experiments that researchers design are pretty clever, and the results can be quite interesting. That aside, I'm not sure just how valuable this information is from a practical perspective. While I do think it's important for UI designers to be aware of how the perceptual system, motor system, and cognitive system work and what their limitations are, it seems that this information is so low-level that it cannot be directly incorporated into the UI design process. Trying to measure this kind of data as part of UI testing would be way too costly for any benefit that it may provide. Most importantly, the complexity of UI design cannot be distilled into a few variables comprised of response time, decay time, storage capacity, and so on. To get results that are truly expressive of human tendencies, behaviors, needs, shortcomings, etc., UI analysis must occur at a higher level than that of the model human processor.
Kevin Nakahara - Mar 02, 2009 04:14:02 am
Obviously there was too much in the reading to discuss in one paragraph, so I'll discuss the two most interesting things I got out of it, the basic model of human computation and the response time associated with keyboard typing. I found that the division of human computation into perception, cognition, and motor skills vaguely mirrored the structure of the model-view-controller. Perception is like the controller, as it feeds data to processed into the processor. Cognition is like the model because it deciphers what to do with the data it receives and translates it into useable data. Motor skills are like the view in that both show the output of the processes going on inside the brain. I also found the average process times given for each individual phase to be pretty interesting as well. When I saw that the reading went in depth into the time needed to process button interfaces, I wondered if it would go into keyboard typing, and sure enough it did. I found it pretty interesting that the QWERTY keyboard was able to outpace the ABCDEF keyboard, but figured it was probably due to users being mostly accustomed to using the QWERTY keyboard. Another reason could be the relative closeness of vowel keys in an ABCDEF keyboard, and how that would make typing more inefficient.
Jason Lo - Mar 02, 2009 04:00:06 am
I found this article not that helpful. The idea of using equations to measure response does not help me design a better interface. It was somewhat interesting reading about how our hands move in increments of smaller motion. I thought about how that would apply to gaming, but it wasn't much help besides that. I liked the details on how sounds and flashes can be indistinct at lower rates that I would have expected. The part about the memory of humans, the amount of stuff that stays in memory, breaking things into chunks definitely made sense to me. Also the psychology is how you remember things can play into creating a design that does not make the user need to remember all the things at once. However the bulk of the article on reaction time and math made little impact me and did not help me think of ways to design a better user interface.
Phiroath Chan - Mar 02, 2009 04:13:36 am
A user interface should play to how a human mind operates. If interface designers understand how humans perceive information they see and how what they see effect how they response, those designers will be very successful. I feel the model human processor deals with this concept. The model human processor is broken up into three subgroups that link together pretty intuitively. Its like one subsystem relies on another. The perceptual system deals with storing all the information coming into the mind though the 5 senses. The cognitive system makes decisions on how to respond based on working and long-term memory. Lastly the motor system carries out the response given to it by the cognitive system. Since all the systems seem to link it would help give interface designers a diagram on how responses are performed based on what was perceived. If the designer wanted to have a particular response he can design his interface a certain way to get the user to respond that way. Problem is how does a interface designer go about predicting human responses to their interface?. I became lost in all the equations, but I'm sure those equations will help interface designers design successful interfaces.
David Burban - Mar 02, 2009 04:16:39 am
I agree with most of the other responses, that this article goes into too much depth and psychology than is necessary. This article models the human as a processor. While this might be applicable on average, I believe that a person's perception is shaped by past experiences and computer knowledge, making the formulas pretty useless if you are certain about the type of users than you are going to be targeting. As far as memory is concerned, that is again based on the user. Even though I've shown my mom multiple times how to program the stock car radio (02' Nissan Sentra), it took her over three years to actually learn to do so. Even when she did learn how to program her radio, she didn't think of applying the knowledge to another radio. In essence, even if a user does learn a basic operation, there isn't a guarantee that they can apply it to something in a similar category.
Alan Young - Mar 02, 2009 04:58:29 am
I think the analogy between the human mind and computer systems is an interesting one and this article does a decent job of presenting the model of the human processor and 3 subsystems: perceptual system, motor system, and cognitive system. I initially thought it was strange that they modeled the human processor's 3 subsystems as all having different processors and memory but when I read further, it made sense because the human mind is more of a collection of interacting systems rather than a single unit. For example, swinging a bat at an incoming baseball is a combination of arm motor movement and eye signal processing. I think this article allows UI designers to design interfaces that can maximize the efficiency of the human mind in utilizing all 3 subsystems. I think this idea is similar to interactive learning, where students are bombarded with information via visual and audio means. This way, students have multiple cues to recall information in the future (long-term memory) and so will be able to recall data quicker. If a designer can minimize user's physical reaction times, enhance visual recognition, then human performance can be improved because the bottle neck in working memory is somewhat relieved by more cues to long-term memory. In this way, UI designers should study what users are accustomed to and what may be in their long-term memory already so that they can take advantage of fast-read long-term memory. I think an interesting connection is with the article a couple weeks ago on modes. In that article, a pilot was asked why airplane interfaces are so complex and replied that the goal was to incorporate all the possible interfaces so that pilots can be familiar with whichever interface they learned first. However, the unintended consequence was that pilots were mandated to learn all the different interfaces and took longer to learn how to pilot. Does a pilot have the ability to act quicker in an emergency situation if he learned the different interfaces and so has more cues for certain tasks stored in long-term memory for fast-read?
Adit Dalvi - Mar 02, 2009 05:13:49 am
I thought this was a pretty long reading; however, I enjoyed the math. I prefer readings where the ideas are presented in 3-4 equations rather than 20 something pages. The main idea I got out of this was that user interfaces should be designed so that they not only take advantage of the user’s short term memory (small capacity) and the user’s long term memory (really high capacity). Basically, user interfaces should be easy enough to use such that in a short time, the user understands how to use the system and can complete the task at hand. If the user spends too much time learning something new, especially when in the middle of doing something, the user might lose focus. Also, by making the user interface similar to the ones already out there, the designer can tap into the long term memory of the user to decrease the learning time for the interface.
Rohan Dhaimade - Mar 02, 2009 05:24:17 am
I can understand the purpose of the article is to give some type of quantitative measure of the user interface, and it works fairly well. Response time can be a good indicator of how well you interface is designed. If something is hard to find, then it is probably a poor interface. If something is not as obvious, then it will take a long time. The only problem I've had is there might be idiosyncrasies that throw off things. I know, when I'm reading something, I tend to highlight words that I'm reading. It's a very strange habit and I don't know why I do it, but I do. So my "habits" might actually throw off data.
I do have an issue with the long-term memory store thing. I mean, yes long-term memory store can be more efficient but then the problem arises that there are better ways of doing things. New changes that could get accustomed might be better off than long-term changes but the short-term benefits when doing quantitative analysis will lean toward the long-term, shouldn't there be some bias added for new interfaces vs using long-term? How would you calculate it?
Szu-Chun Mao - Mar 02, 2009 05:48:39 am
This article is difficult to get through due to all the detail calculations on the processing and reaction time, however, using the model human processor makes it easy for us to understand how we process information like computers. The model human processor is divided into 3 subsystems: perceptual, motor, and cognitive system which allows us to analysis the reaction time in each subsystem. Therefore it provides us a method to test our user interface with number result. I’m uncertain how this concept can be applied in real world easily. If this model is that easy to test our user interface and come out with accuracy result then we can all standardize our user testing and evaluation procedures with great outcome. However, the truth is it’s not that simple even with all the variables and complex calculations. On the other hand, I do feel that the explanation of working memory and its relation to long-term memory is more helpful in term of building an easy- to-use UI.
Alexander Cho - Mar 02, 2009 05:58:12 am
It was very interesting how they tried to quantify the human perception and processing with all these equations, graphs, and numbers. I never thought such detailed studies were conducted on the human perception. I suppose I can see the connection between computer processing and human processing now (which is why I assume cognitive science majors have to take computer science courses). I wonder what numbers and findings would be most useful for the purpose of our project to attune our UIs to the limitations and functions of the human perception.
Derek Liu - Mar 02, 2009 06:29:47 am
I found this article very difficult to get through with far too much mathematical data for my tastes so it was fairly hard to get into the reading. This article, however, provides some useful insights on the study of human behavior and reasoning which also allows helps user interface design if we know how peoples' minds work. However, the level of detail that the article provides is astounding and went over my head most of the time while I was reading. Creating a good interface design does not require a person to get down to this level of detail when studying human mind and behavior.
Bernardo de Seabra - Mar 02, 2009 06:36:03 am
The authors of "The Model Human Processor" describe the human mind as an information-processing system. This system is further sub-divided into three other: perceptual, motor and cognitive. The perceptual system reacts to the information received by the sensory system by making decisions based on Long-Term Memory. The time it takes for such reaction to happen is measured in terms of "unit impulse response" which varies inversely with the intensity of the stimulus. The motor system reacts to the translation of a thought into action by activating patterns of voluntary muscles. This system is primarily responsible for our body movement and reactions. The cognitive system server the purpose of glueing together the two systems mentioned above. It contains cognitive memories that can be subdivided into two types: working and long term memories. The working memory is where the mental operations of the brain occur and results are stored. It is similar to a scratch space used for temporary storage of data. The long-term memory, on the other hand, is a persistent, non-erasable storage medium that is responsible for holding an individual's knowledge. The authors discuss in detail how the information is organized (chunks) and how it is organized for retrieval (sort of tags). They also explain the reasons why although some piece of data that might reside in the long-term memory might not be accessible. The authors also cover how to measure times for processing information and executing tasks as well as factors that accelerate and slow down such executions.
Prahalika Reddy - Mar 02, 2009 05:58:18 am
The article analyzes the human brain and it's inner workings in order to understand how humans perceive things. The ideas in this article are very useful for user interfaces. Understanding that users access both short term memory and long term memory when performing tasks is helpful to know when designing interfaces. Also, I completely agree that if there are two similar tasks but the interfaces to perform those tasks are different, it will definitely take more time and energy to recall how to perform that task in either of the interfaces. The other ideas in the article were also useful, but I think trying to reduce human thinking and the perception process into all the equations isn't completely accurate; since everyone is different and have used and experienced different things, their interaction with any interface will be based on their other experiences, instead of in a completely mathematical way.
This article was too long and went into too much detail. All the equations and charts in the reading were confusing and uninteresting and I just skimmed over them.
Chao Michael Zhang - Mar 02, 2009 08:41:44 am
The ideas presented in the reading can be applied to user interface design by providing a quantifiable way to assess the quality of an interface design. Applying some of the equations for the "human processor" can help interface designers have a framework around which to design their interfaces. This has applications for everything from how much text to put on a page, to the spacing between elements, since there are measurable speeds of thought and eye movement. The designer could also use these equations to take into account the speed of perception.
Salman Rahman - Mar 02, 2009 09:32:48 am
Again, we were presented with a unnecessarily challenging and dense reading. The information that was presented though would be useful in developing a highly calculated UI - though I think that level of detail is not required for a lot of implementations. A lot of what was presented could be useful in a more complex interface; i.e. the authors presented placement of keyboard layout for optimal convenience of user, etc. But if we were designing a simple interface like for our individual coding project, I can't see the benefit in wading through all this material to maybe improve the user's task time by a second or two.
Sum Sum Wong - Mar 02, 2009 08:56:32 am
I thought it is an interesting idea to model human brain with a processor. Yet I think it is a bit over to quantify everything and put them into equations since a human brain is a lot more complicated than a piece of CPU. The reading suggested that acoustic memory can last longer (decay slower) than the visual one(which I think combine acoustic with visual is way to go. For example, when remembering a series of words, if we only have the words speaken by another person, its hard to remember. The better way is to see the words, and read them aloud by ourselves). However, the idea of "acoustic over visual" can hardly be used in designing UI. Imagine if we have an application when user click on "instruction", the visual instructions will appear on the screen with a sound reading out the instructions as well. I guess most user will just igore the sound(or mute) because we don't have the luxury of time to hear everything since reading a paragraph is a lot faster than hearing one.
Anjana Dasu - Mar 02, 2009 09:54:12 am
The number of equations/calculations in this article made it extremely difficult to focus/read at my usual pace, so I didn't really enjoy reading this. The authors even used something reminiscent of a chemical equation to describe rational behavior: Goals + Task + Operators + Inputs + Knowledge + Process-limits -> Behavior (I mean, really, was that necessary?).
Equations aside, I thought the Discrimination Principle and the idea of interference were very applicable to user interface design. It's going to be harder for a user to remember what to do if there are two very similar items in memory. Also, if a user has already learned one system, and a similar system has been designed with slight differences, he will have problems between the two (they give the example of a text editor with different command names).
Eric Hernandez - Mar 02, 2009 10:12:58 am
This article seems to be filled with tidbits of information that are useful in UI design. The decay of visual and auditory images stores shows would suggest for example that it would be bad to have an interface where one of its modes or screens depends heavily on the previous but now unseen mode or screen. "Memory Chunks" could also be important in large applications with many features. Throwing features together and correlating them in particular ways could be done in a way that attempts to maximize the average brain's ability to "chunk" together how to use the system. Although this idea is somewhat obvious, it would be good to study exactly what kind of feature clumping results in good memory formation for users. In my opinion, the rate at which people can match objects was the most important part of this paper in terms of UI design. It's interesting that digits can be matched with other digits faster than anything else they tested. Could this somehow mean that using digits, colors and letters (the fastest 3) in UIs could be fast and efficient in a user interface?
Shendy Kurnia - Mar 02, 2009 10:06:55 am
Wow, this reading has a lot of numbers and equations. However, I think the summary is that working memory lasts shorter than long-term memory (obviously from the name). Also, visual memory has bigger capacity than auditory memory, but visual memory decays faster. There are a lot of information more than that from this reading. In designing user interface we can make a use of this information. For example, in order to make a good tutorial of a program, we can use visual tutorial since it last longer in user's memory. We can use sound to notify user of warnings, errors, or event occurrences since it stays longer in user's mind. Furthermore, we should make sure that user does not need to do some sequence of actions that clatter his working memory so that he is not drawn away from what he was doing.
Alexei Baboulevitch - Mar 02, 2009 10:46:00 am
Although the article's theoretical results confirm the experimental results in all the examples, it would be very dangerous to apply this methodology directly to interface design. It would perhaps be akin to measuring an application's speed by analyzing the timings of the circuits: an extremely low level view that might occasionally be accurate, but which effectively ignores the vast complexities of the machine. There is so much about the brain that we don't know, and using these approximate timings for certain theoretical brain subsystems (which may or may not have a physical basis) is sure to lead to error.
Siddharth Shah - Mar 02, 2009 10:39:49 am
This article was really long and complicated. All the equations were interesting and it's cool to see that people (experts) have taken the time to develop these equations and compile all the information that was presented in the reading. However, for all this information to be useful, we have to be able to actually REMEMBER it. The length and complexity of this article makes it fail in this regard. I will probably have to re-read the article a couple of times before I can claim to understand it.
Aaron Hong - Mar 02, 2009 10:44:40 am
This is a fascinating reading especially the stuff on memory (working and long-term). This is especially useful for our group since we are going to be dealing with a memorization game, and it is good to understand what we are trying to do cognitively because that is what our game is... to deal with someone's cognitive process. We are given knowledge now to understand with finer granularity what we are trying to do: move information from working memory into long-term memory. One thing that does help is repetition and increasing the number of association with other items in long-term memory. Also it gives us clues on how to break down the information into memorization "chunks." Lots of interesting stuff we need to ruminate over.
Andrew Chen - Mar 02, 2009 10:57:45 am
It is interesting that this article maps human cognitive functions to computer processors; it makes me wonder, however, how accurate such an analogy is, and, more importantly, how do they actually know the things they seem to present straightforwardly as if self-evident, such as the Visual Image Store and the Auditory Image Store? I cannot imagine how those could be measured or observed even with brain scans!
