Human Information Processing

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The Model Human Processor Chapter 2 of The Psychology of Human-Computer Interaction. Card, Moran & Newell. Only Pages 24-76.

Reading Critiques

Guoyang Huang (Guh6) 21:20:51 2/3/2014

Chapter 2 focused on a lot of empirical data and equations which I do not have a good understanding of. However, I did learn about the model human processor that distinguishes the simplified account of the present model that uses perceptual system, motor system, and cogitative system. First, the cognitive perceptual system includes the sensory system and the perceptual memory. The perceptual memory deals with the auditory and visual sensory in working memory. Additionally, the perceptual processor deals with the impulse response or the time response of the visual system to a very brief pulse of light. Second, the motor system was discussed as the agonist and antagonist analogous to muscle and to the arm-hand-finger and hand-eye pair for computer users. The motor system deals with the physical means of a user helped by a third concept of the cognitive system. The cognitive system deals with the connection between the perceptual and motor system to create the correct output. In it, I learned about the working and long-term memory studied. The working memory is the intermediate product of thinking that all operations use it whereas the latter holds user’s mass of available knowledge. The key between those two is to create an associate or link between the working and long-term so long-term memory can be accessed faster. Another thing I learned is the cognitive processor is like the fetch-execute cycle that takes about a tenth of a second which makes performing action serializable unless paralleled. The third conception I learned dealt with laws and observations made based on the data in the text. The three models mentioned was slowman, middleman, and fastman for parameters to be considered for the speed. I also learned about perceptual causality of it takes 100 msec for the frame and 50msec for computation for two objects seemingly to move caused by the other. Fourth, Fitt’s law was used to calculate the time of placing objects at certain location to reduce response time. Fifth, the power law of practice says that time to do a task decreases with practice because of cognitive sensory and motor. I learned through the data that response time is greatest from class, name, physical to simple where each delay is about 70msec from the preceding. Lastly, the relationship between response time and number of options is not linear because of the ability to arrange processing hierarchy into groups mentioned by Hick’s law and principle of uncertainty.

Sara Provost 18:32:57 2/4/2014

This week’s reading was about the human as a processor. According to the reading there are three subsystems that the human mind can be divided into they are: the perceptual system, the motor system, and the cognitive system. Much like a computer each of these systems has its own memories and processors. The perceptual system is the system that carries the sensations of the physical world to the mind, the most obvious example of this being the ability of sight. Every sensation that this system brings in to the mind is converted to a visual memory and stored for later use. Similar to digital memory, these visual memories will decay over time. The second subsystem of the mind that exists is the perceptual processor, which controls impulse response. If these impulses occur close enough together, they will be stored as a single perception and will be interpreted as a longer impulse. These impulses are converted into action via the motor system, which allows a person to respond to their environment. The final subsystem of the human mind that is discussed in this article is the cognitive processor, which is analogous to the fetch-execute cycle of the standard computer. In other terms, the cognitive processor is responsible for the fetching of current memory information, linking it to other relevant memories, and responding appropriately. The second important concept that this reading discusses is the idea of human performance. Human performance can be broken down into three parts: task analysis, calculation, and approximation. The reading discusses human performance in terms of speed, some examples given are this such as reading speed, typing speed that improves with practice, decision-making times, and reaction times. The reading discusses in depth the process by which each of these occurs and improves. Finally, the reading discusses memory. According to the reading memory occurs in discrete chunks, and can be made stronger via repetition. Human memory is limited by its size and how it is processed. It is also important to note that human memory can be stronger in some places than others. Human memory also decays due to interference from similar memories and displacement by newer memories. I think that this reading will be helpful with the second part of the group project, and with future parts of it. This article increased my understanding of the human mind and how similar to a standard computer it is. In the course of the group project we will have to ask users to act as a computer and work their way through our mobile interface. With the information from this article I will be able to better understand the reasons behind user choices, why they react the way they do, and how I can better design an interface that will suit their needs.

Buck Young 23:37:24 2/4/2014

This reading was interesting as it considered the human mind and responses as that of a machine. This structured outlook allows for the creation of many mathematical formulas that have plenty of applications for a mobile interface. Firstly, there is a perceptual system which accounts for how long it takes to processes certain types/amounts of data. There is a cognitive system which is responsible for memory. The book even considers "human performance" -- the rate at which we can read (process data) and perceive moving pictures. There is also talk about the motor ability of the human hand. All of this comes together to help people like us create better interfaces. I found the section written about the different keyboards to be very interesting. I have experience with other types of keyboards (Colemak) and find the topic fascinating. Current QWERTY keyboards are a relic from the days of typewriters -- the needs and requirements were very different then. Let's usher in a new era of keyboard layouts!

Steven Bauer 0:33:48 2/5/2014

This reading was called the model human processor. The model human processor is a set of memories and processors together with a set of principles of operations. This is further divided into the perceptual system, motor system, and the cognitive system. The perceptual system is how the body is able to make sense of the world around it. Perceptual memories hold the information we have perceived physically. The motor system, the most important of which, for computer scientists like us, are the finger and eye systems. They talk about an example where they had individuals try to scribble between two lines and the delays incurred when they screwed up and went outside the lines and how long it took for their eyes to notice it and have their muscles fix the problem and draw more inside the lines. The cognitive system is what connects the perceptual system to the motor system. The two main parts of this system are the working memory and the long term memory. They go on to describe how memory works and also the working memory's decay rate which is the rate at which short term thoughts are lost. The next major section is human performance in which the author talks about engineering of the human-computer interface using predictions we can make about people. Because this is not an exact science they suggest that we anticipate the worst performance, best performance, and middleman (nominal performance). The first example they talk about is calculating a frame rate that will make the video smooth for all users. They go on to talk about reaction times, reading rate, and other factors that go into a person operating/interacting with a machine. This was an interesting article because unlike technology which is constantly improving, the human body has remained pretty constant for the past several hundred years and we need to take in to account the body's limitations when we design technology.

Xiaoxuan Chen 2:30:16 2/5/2014

The reading described the human mind as an information-processing system; this model is called Model Human Processor. It can be described by a set of memories and processors together with a set of principles. Model Human Processor can be divided into three interacting subsystem: perceptual system, motor system, and cognitive system. Each subsystem had it's own memories and processors. The perceptual system carries sensations of the physical world detected by the body's sensory systems into internal representations of the mind by means of integrated sensory system including Visual Image Store and Auditory Image Store. The cognitive system receives symbolically code information from the sensory image stores in its working memory and uses preciously stored information in long-term memory to make decisions about how to respond. The motor system carries out the response. Characteristics of the memories and processors can be summarized by the following parameters: processor cycle time, memory capacity, memory decay rate, and memory code type. This model helps us to understand, predict, and calculate human performance relevant to Human Computer Interaction. In order to evaluate human performance, the reading mentioned a technique that is used to find the uncertainties in the parameter of the Model Human Processor is by defining three versions of the model: one in which all the parameters listed are set to give the worst performance, one in which all are set to give the best performance, and one set for a nominal performance. The reading used many examples to explain evaluation of human performance. Similar visual stimuli that occur within one perceptual processor cycle tend to fuse into a single coherent precept. One way for two distinct stimuli to fuse is for the first event to appear to cause the other. Two basic movement occur in Human Computer Interaction are: movement of the hand towards a target and keystrokes. It's good to remember that the time to do a task decreases with practice - power law of practice, which plays an important role in understanding user keystroking performance. Power law of practice has three practical consequences: a wide spread of individual differences based primarily on the amount of previous typing practice, the power function form for the practice curve has a very steep initial slope, the practice curve becomes relatively flat after a short time. This reading continue to introduce how the perceptual and motor systems together with central cognitive mechanisms combine in simple acts of behavior. It introduces simple reaction time, physical matches, name matches, class matches, and choice reaction time, including the uncertainty principle that decision time increases with uncertainty about the judgement or decision to be made. Learning and retrieval section talked about how knowledge about systems and procedures is stored and retrieved. It included topics on forgetting just-acquired information, interference in working memory, interference in long-term memory and search long-term memory. Then it gives a deeper look into complex information-processing by operator sequences, rationality principle - a person acts so as to attain his goals through rational action, given the structure of the task and his inputs of information, and bounded by limitations on his knowledge and processing ability, and problem space principle - the rational activity in which people engage to solve a problem can be described in terms of a set of states of knowledge, operators for changing one state into another, constraints on applying operators, and control knowledge for deciding which operator to apply next. At the end it discussed boxes vs depth of processing, working memory span, memory strength vs chunks, interference vs decay, and the expansions of the model human processor, as well as the existence of alternatives. This reading gave me an in-depth idea of Model Human processor, it's components, and the function of it. Knowing this is very useful for me when I'm conducting a research in the related area.

Cody Giardinello 12:48:59 2/5/2014

This reading talks about humans in terms of computer terminology. It is interesting to see how the author describes our minds in these terms. He lays the foundation of The Model Human Processor as being as a set of memories and processors together with a set of principles which the author calls the “principles of operation”. Within this general scope, there is a collection of 3 subsystems – the perceptual system, the motor system, and the cognitive system. The perceptual system carries sensations of the physical world to the mind. After the visual stimulus comes in, it appears as a Visual Image Store inside the brain. The author goes on to describe the mechanics of the VIS and how it saves information about visual stimulus. Interestingly, the VIS decays quicker than the Auditory Image Store. Next, the author describes the Motor system. Here, thoughts are translated into action by the human. The author provides many equations showing the time messages take to get from the mind to the body part and vice versa. This is called the cycle time of the Motor Processor. Lastly is the cognitive system in which connects the perceptual and motor systems together. As with perceptual memories, there are cognitive memories as well. These include a working memory and a long term memory. The reading goes on to show more equations outlining the timelines of these memory types and their functions. The next section is about human performance. This section is summarized by use of examples such as pictures stitched together to form one image or how Morse-code is taken in to the perceptual processor. These examples are outlined in detail along with others, showing the response rate and the time it takes the human processor to react appropriately. A very interesting part of this section is about the layout of the keyboard and why it is QWERTY style and not alphabetical. The study showed more than 5 words per minutes were typed with the QWERTY keyboard than the other. The last section is about reaction time. There are different stimuli that can cause reactions to be seen. These range from physical matches to name matches, all the way to choice reactions. Choice reactions are just when a choice is delivered to a subject and a decision must be made. Towards the end of the reading, the author shows more charts and equations that depict learning and retrieval. These can be seen through both the working and long term memory. Interestingly but not surprisingly, the ratio between the two in terms of decay times is 1:35; a vast difference.

Brian Kacin 17:42:42 2/5/2014

The article is talking about the Model Human processor. Which is about the psychology and physiology of how a person takes in memory and where it is stored in the brain. The Model Human processor is divided into three interacting subsystems: the perceptual system, the motor system, the cognitive system. Starting with the perceptual system, which by its name, takes senses of your perception of the world and represents that to your mind. For example, the perceptual processor takes what you see and hear and puts it into visual image store or auditory image store. As for what memory is the strongest, it is the auditory memory. Which could be a good queue for when you want someone to remember something. The next system mentioned is the motor system. This is memory through actions of your voluntary muscles. For computers and mobile applications, the most important are the arm-hand-finger system and the head-eye system. Last but certainly not least, is the cognitive system. This system tries to connect the inputs from the perception system and makes outputs for the motor system. There are two types of cognitive memories, working and long term. The working is memory that is under current evaluation and long term memory is memory for future references. However, for appropriate retrieval of the long term memory, there must be associations connected to it that are mapped or it will not be found. That’s why certain songs and things that are not directly related can spark memories, as long as the association is there. Knowing this can go a long way in marketing or creating a mobile application. Along with memory for all these systems that interact with eachother, doing a task for the first time compared to practicing it and doing the same thing later, always takes less time because of memory to the brain and the senses. That’s why we can type faster, throw a ball with more accuracy, solve similar equations faster with practice. An interfere in working memory is trying to remember similar items in memory. The brain maps them to similar parts of the brain, and when it comes down to it, it gets interfered with and can be mixing up the arrays of memory. This also applies to the long term memory spectrum as well. In conclusion, we should make things that are good for the user to remember and will remember for a long time.

Hao Zhang 20:05:18 2/5/2014

This chapter introduce us how human body processes (the information and reaction of human body), such as memory, vision, senses and so on. It helps us to design software that is closed to human, and make human comfortable with it. For many if not most systems, interfaces with human users likely represent the most success-critical components. The interface, to the user, is the system. Management information and decision support systems require regular interaction between the system and decision makers, its users. The information system design, especially with respect to its user interface, often dictates how a great deal of the work of an organization will be performed, the order of task performance, and the importance of individual tasks. Ultimately, the effectiveness of the interface in structuring, facilitating, and supporting the work of the organization will affect the achievement of organizational objectives. To understand good system design characteristics, it is important to understand how humans process information. Two model frameworks, a general model and the Newell-Simon model of the human as an information processor, may be helpful in understanding the concept. Tentative limits on human information processing capabilities and the relationship between information and performance, along with related concepts and research from other fields, may provide additional insight.

Melissa Thompson 21:18:14 2/5/2014

This reading compares the human mind to a computer information processing system. The model human information-processor is described by the author as perceptual, motor, and cognitive systems, each of which contain a set of memories, processors, and principles of operation. Each system is broken down into components and described in a way that is similar to how computer systems are described. The perceptual system for example receives and stores detected sensations based on type, time, and other "parameters". This data is stored in a memory, which has a decay time (i.e. the memory of the stimulus fades over time). In addition to the formula for memory decay, the author also provides formulas for the "cycle time" of the perceptual processor, or how often a pulse of light is received and processed by our retinas. This processing time is not constant; it varies based on conditions like how intense a stimulus is. The motor system is the second system that the author discusses in technical terms. This system processes thought into micro-movements, which also has it's own cycle time. There is a max rate of output for muscle movement, much like how there is a max speed for a computer to output data based on it's own processor. The cognitive system is the system that connects the first two with working and long term memories. The processor of this system uses a cycle similar to the fetch & execute cycle of a CPU in order to recognize input and perform an action. Human processor performance, like CPU performance, is based on analysis, calculation, and approximation. Since it is hard to pin down exact parameters for "human" calculations, as all humans are different, a range of values is used to simulate the average human, a fast one, and a slow one. These can then be used to analyze potential performances of perception, motor skills, decision making, learning, and problem solving. The purpose of studying these parts of human model processor performance is to be able to relate them to computer interaction. For example, by knowing the rate at which light cycles through our retinas, we can also know how fast a screen needs to flicker in order to simulate movement. How fast can we hear a sound? How fast can we read text, move a mouse to a target, or press a key? All of these computer interactions are limited by a humans processing power. The author goes into detail for each of these human-computer interactions, using information about human performance to determine the most ideal computer interfaces. Even keys on a keyboard are arranged to optimize human performance; the current keyboard layout is calculated to be about 8% faster for typing than one ordered alphabetically, for example. The overall conclusion of the reading is that computer interfaces need to be designed in order to accommodate the time it takes for the human perceptual, motor, and cognitive systems to process and react to data. So analyzing model human information-processor information with calculation and analysis helps to do this in the best way possible.

Zach Liss 21:37:54 2/5/2014

Today's reading was about Human Information Processing. We began by reading about the Model Human Processor. It can be divided into three interacting subsystems: the perceptual system, the motor system, and the cognitive system. The perceptual system carries sensations of the physical world detected by the body's sensory systems into internal representations in the mind. The motor system is the action that the body takes after thought. It translates thought into voluntary muscle movement. Finally the cognitive system. It has two main types of memory: a working memory to hold the information under current consideration and a long-term memory to store for future use. Thinking of the human body as a processor will help us develop an app that is efficient for people to use. Our product gets much better when we are able to take into account all of the work the human body needs to go through to perform its operations.

Matthew O' Hanlon 22:11:47 2/5/2014

The first section of the reading explained about the brain and how it perceives images and processes those images and outputs motion. The model human processor has three interacting subsystems, the perceptual system, the motor system, and the cognitive system. Each of these has their own memory and processors. The perceptual system deals with auditory and visual sensory stimuli. The perceptual processor deals with impulse response and time responsive of visual system. The second section of the reading dealt with the Motor system. When the motor system is involved it means that his brain has translated information that has been perceived and muscles are being moved consciously in reaction to the external stimuli. These muscles are arranged in pairs each pair has an opposing muscle one is called an agonist and the other is called an antagonist. The third section of the reading discussed the cognitive system. The cognitive system acts an intermediary between the perceptual system and the motor system. The perceptual system is the input and the motor system is the output. There are two types of memory in the cognitive system, working memory, and long-term memory. The working memory has most of the action, as it takes on the responsibility to process information quickly and make connections with existing data. The long-term memory serves as a kind of database where the working memory can call on it to make connections with new input. The last section dealt with laws and observations made based on the data collected in the research. The three models were developed to describe the kinds of variance in the data which were the slowman, the middleman, and the fastman. Each are parameters to be considered for speed. Fitt’s law is a good example of the aforementioned described inaccuracies. It describes how motor skills are not completely accurate and motions are small discrete corrections towards the goal. The power law of practice seems to bolster the theme of small corrections. It says that time to do a task decreases with practice.

Aamir Nayeem (aan14) 22:34:23 2/5/2014

Today's readings were kind of interesting. It's interesting to think of a human as a computer. It's also important because it makes one realize that, like computers, humans have limitations, which is important to consider when we think about both our expectations for what machines should be able to accomplish and what sorts of problems we could address to help humans with their shortcomings. Unfortunately, after a while, the reading kind of felt repetitive. It was an interesting idea, but it didn't really seem like it was building up to anything, so I started to lose interest. Conceptually it's a cool idea to think about, and it seems like there's a lot of research done on our thresholds for memory and our mental capacity, but I guess I kept expecting it to go somewhere from there and it didn't.

MJ McLaughlin 22:40:45 2/5/2014

This chapter of “The Psychology of Human-Computer Interaction” provided a really interesting way of looking at the human mind as an information-processing system. By looking at the mind this way, as a “Model Human Processor” consisting of memories, processors, and principles of operation, it becomes possible to model how we think and process information, and apply these models to real-world applications. According to this model, the brain can be subdivided into three subsystems that are the perceptual system, the motor system, and the cognitive system. Each of these subsystems interact with each other and have their own memories and processors, such as the visual and auditory stores of the perceptual system, all of which process information and produce outputs, such as behavior, and can be described using parameters including storage capacity, decay time, code type, and cycle time. The perceptual system is the system that takes sensations, such as visual and auditory stimuli, and converts them into internal representations in our minds. These stimuli temporarily reside in the appropriate image store and also have decay rates which limit, for example, how well these sensations can be utilized in working memory. If multiple sensations are received within one unit of processing time for the perceptual processor, they can even blur together, but this processing can be sped up with more intense stimuli. The motor system is that which converts thought into voluntary action, such as hand movements. These movements are not actually continuous, but rather consist of micro-movements that last for one cycle time of the motor processor, usually around 70 milliseconds. These movements are dictated by the rest of the human information processing system, which can also carry out such actions as self-corrections of movements. The cognitive system can simply act as a connection between inputs from the perceptual system and outputs from the motor system, but it is also the system that processes the many more complex actions we carry out that involve such steps as learning, memory retrieval, and problem-solving. Working memory and long term memory collaborate to process all sorts of complex information, with working memory, for instance, able to take information from long-term memory when needed as well as store new information in long-term memory. Like the perceptual system, working memory also has a limit to how much information it can process at once, and information is also stored and accessed in a way determined by certain retrieval cues. Retrieval can be interfered with by other memories as well. All of this cognitive processing occurs within the “recognize-act cycle,” which consists of linking the contents of working memory with actions in long-term memory, which then modified the information working memory, setting up the next cycle. The time required for such a cycle can be increased with greater demands or information loads, and decreased with greater effort and practice. All of this information becomes very useful in modeling the performance of humans when carrying out a wide variety of tasks. As this type of modeling is just that, a model, it is useful to think of extremes of processing ability as slow, medium, and fast and to use these as guidelines when thinking about actual human performance. We can, for example, model how fast pictures must move to give the illusion of movement or how quickly we can process Morse code, as well as reading rate and the perception of causality. Fitts’s Law can be used to model movements of the hand towards a target as well as keystrokes, two abilities very relevant to our goal of interface design. And these physical abilities can be enhanced by practice, as well as through the use of different methods such as two-handed typing or different keyboard layouts. Behavior also relies heavily on cognitive processing such as reaction based on decision making. Different classes of such decisions, including physical, name, and class matches all require different amounts of processing and thus different amounts of time to process. And this processing can take longer with more choices to be made in responses as well as with uncertainty in decisions. By looking at the human mind as such an information processor, we are able to think about and model our abilities and behaviors in a way that helps us to understand what we are capable of. And this is incredibly useful in our pursuit of interface design as by knowing how people think and what we’re capable of, we can design our interfaces and applications accordingly. We don’t want to overload people with information or cause uncertainty, but we rather want to design our interfaces in a way such that information is supplied in an appropriate manner and with feedback that helps people practice important actions and become comfortable and certain with them. We don’t want buttons to be too close to each other and too cluttered, but rather we want important actions to be featured prominently. By thinking about the mind as a “Model Human Processor”, we can think about how to design our interfaces in such a way that they best help people.

MJ (Mary Letera) 23:31:13 2/5/2014

Today's reading talks about "the model human processor". It compares the human mind to an information-processing system. It is subdivided into three subsystems, which interact with each other: the perceptual system, the motor system, and the cognitive system. The perceptual system, as one would guess, is concerned with sensory input from the 5 senses. There is an associated perceptual memory. How persistent this memory is depends on several factors, such as the complexity of the stimulus and the length of time that the stimulus was perceived. The motor system is concerned with physical movements. With regard to computer usage, the subset of this area that is of most notice is that of the hands and eyes. The cognitive system is perhaps the most abstract - it can be related to the metaphor of a processor. In one example given in the text, it connects the data from the perceptual system to some response set off by the motor system. Thinking of people this way is interesting and can be highly beneficial when designing interfaces. For example, a designer needs to take into consideration how one will perceive parts of an application, how they will need to physically interact with an application, and how they can use both of these things to some useful end.

Nicholas Amoscato 23:31:37 2/5/2014

In the second chapter of their book “The Psychology of Human-Computer Interaction”, Stuart Card, Thomas Moran and Allen Newell introduce the concept of the Model Human Processor. This model consists of three subsystems: the perceptual system, the cognitive system and the motor system. The perceptual system contains sensors and their respective buffer memories. For example, the visual system involves the transmission of sensory information via the retina to the Visual Image Store, a sensory memory that holds information coded physically. From here, the information is encoded in the cognitive working memory. The unit impulse response denotes the cycle time it takes for light to process. The motor system carries out the response by activating patterns of voluntary muscles, and the cognitive system receives information from the perceptual system and long term memory. There are two types of memories in the cognitive system: working memory and long term memory that store current and future information respectively. Working memory stores a small subset of active chunks, of which only five to nine can be easily remembered at a time. Long term memory stores the entire mass of a user’s available knowledge. Next, the chapter discusses the implications of measuring human performance. In particular, the idea of perception is explored in which there is a limit where humans can no longer attend to sensory input. In addition to perceptual performance, motor processors also have a limit. The movement of a hand towards a target is defined by an equation called Fitt’s Law. A second type of motion, keystroking performance is severely affect by practice – that is, the time to do such a task decreases with practice. When it comes to retrieving information, information that was input over a few minutes must be retrieved from long term memory. Also, it is more difficult to retrieve an item if there are other similar items in memory. This occurs especially in long term memory where items are retrieved via the same cues. The tasks described thus far were relatively simple; however, in reality, user behavior is quite complex. The rationality principle states that a person acts to obtain a goal through rational action which includes tasks, operators, inputs and knowledge. The chapter closes with a set of alternative views that expand on the prior concepts described.

Zhanjie Zhang 23:32:40 2/5/2014

The chapter begins by describing the human mind as an information-processing system. The model human processor can be described by a set of memories and processors together with a set of principles called the principles of operation. This is an interesting thought in where it discusses the human system as a perceptual system. It is something that carries sensation of the physical world detected by the body’s sensory system. This is important to be understood as it allows the reader to understand how to design proper interfaces for the user. It is also important to be aware of the human’s motor system which is part of the human’s perceptual system. By having understanding how human’s motor system is designed, we can better understand human’s abilities. Also being aware of cognitive abilities is important. Knowing the rate that working memory decay in working memory is very interesting which implies that user interface designed must be simple. These three main subsystems: perceptual, cognitive, and motor system combines to make the Model Human Processor. This allows us to understand, predict, and calculate human performance relevant to human computer interaction. Understanding human performance also is important. One of it is perception; an example given is the Morse code listening rate. Also, observing how humans do well in different situations is also important in helping us understand how humans perceive. For designing user interfaces, it is important for us designers to be aware of human’s abilities. By understanding them, they can develop the best interface for their applications.

Ariana Farshchi 0:44:52 2/6/2014

This weeks reading, The Human Information Processor explains that the human mind is an information-processing system, and gives us a model, which is outlined in this chapter, which is described by “a set of memories and processors together with a set of principles”. The human processor can then by divided into 3 interacting simultaneous systems: the perceptual system, the motor system, and the cognitive system. The author describes each system in-depth. The perceptual system consists of sensors and associated buffer memories. The cognitive system receives symbolically coded information from the sensory image stores in its working and long-term memory to make decisions on how to respond. The motor system carries out the response. This model of human cognition can be used to provide insight and predict user-computer interactions. The model is useful for the design of user interfaces, because it provides information on how users react to visual and auditory stimuli and how memory is used to process these stimuli.

Michael Mai 0:45:55 2/6/2014

This article was very long and it talked a lot about the human mind. There were many graphs detailing the abilities of the human mind. I thought the most interesting segment was the one talking about forgetting recent information. There was a graph accompanying the data and it showed which words are usually remembered. In the graph, it shows that most of the time, only the first and last words are remembered from a list in recent memory. This is very interesting because there is another research that I read where human minds don't need to see all the letters in a word, they only need the middle letters and their mind subconsciously knows what the word is even if the other letters are jumbled. This reminds me of that because it shows that people don't pay their full attentions at all times. They are most alert at the beginning of an event and at the end because there is a change coming up. Also, the part about long term memory was pretty interesting. The reason is because somehow they came up with a formula as to how people retrieve this long-term memory. The searching of the long-term memory takes a while but a lot of the information can be retrieved. The example with the girl remembering her old high school classmates showed how she scanned her mind for faces, old parties, and other methods. These methods all helped her come up with more names. Overall, I think the article was a bit too drawn out but it had some interesting points. I didn't know you can derive formulas for memory but somehow this author figured out a way. It was interesting to see even though I don't know if it is truly accurate.

Longhao Li 0:55:32 2/6/2014

In this article, the author start with a concept called Model Human Processor, which can be explained as a set of memories and processors together and a set of principles, and the author described the concept in detailed by three interacting subsystem. The perceptual system is a system that transfers sensations of the physical world to the meanings in brain. The motor system is the system that control people’s motions. The cognitive system is the system that working to care about learning, retrieval of facts or solving problems and also connects perceptual system to the motor system. The author describe these three system with the analysis of the memories and processors of different system to tell us how human beings conduct their behaviors, and what kind of mechanisms trigger these behaviors. Then the author talked about the human performance. It is used to predict the performance of Model Human Processor so that the engineers can design the correct interface to make sure the Model Human Processor works properly. To predict the performance of the Model Human Processor, the author uses three versions of model: worst performance, best performance and nominal performance. The guide the development of human-computer interfaces. As the same as what the author did in the description of Model Human Processor, there are a lot of detailed analysis of human performance like memories, and reaction rate. Plenty of numerical data gave the reader a clear understanding about what is our limitation and how to make people get the best performance. This knowledge is a great source for the development of human-computer interface. They can guide the developers to make the right software for human beings. It is important to make human beings satisfied with the software not the computer because computers are serving people. If people cannot get benefit from it,people will not have interested to use it. Great article.

Chris Solis 1:44:37 2/6/2014

The reading focused primarily on human processing. It lies out a model called the human processing model which describes how humans process things through different senses such as perception. The next sections explain in great detail the ways that humans record things. It provides examples such as color and the different parts of the eye and each parts purpose. It also explains how humans process images and the actual mathematical models used to attempt to describe memorization by humans. One can see that human memories of both audio and video decay over time. The next section focuses mainly on the cognitive system. This system's purpose is to take input from a sense and project it through the correct output. Its main focus is on working memory and long term memory. Essentially, working memory is what the is currently being perceived and the brain must make a decision what to store in long term memory. There is much math and in depth analysis covered when it comes to memory decay. The next section focuses on human performance. It focuses on tasks and different methods to enhance the human processing model to attempt to predict what will most likely happen. Different examples such as turning pictures into motion and audio learning are used. The reading was very dense but had a lot of great insight into humans and the ways that we process things.

Alex Stiegel 2:36:28 2/6/2014

This article is describing the human brain as a computer relating all the parts together. The computer parts. They are like your human parts. So the processor is like your eyes. It's crazy man. You take so much data in, but you only process a small percentage. That's crazyyyy. Short term memory. There's only so much and it's pretty fast. This is like RAM. It's pretty cool. It's not as fast as the processor though. Long term memory is next. It's like obviously like the disk drive. It's pretty slow, but keeps it for a longer period of time. It's pretty neat. NEXT PART: Visually searching for an object in a menu is slower than keyboard shortcuts. Remembering the keyboard short cut takes like a millisecond where as searching is a few seconds. That's a crazy difference. It's a really cool fact.  :DDDDDDDD This article oversimplifies the human brain by comparing it to a simple computer. For example, memorizing things can improve access time which cannot be compared to the cache. And now I'm done. Goodnight.

Matt Landram 4:04:19 2/6/2014

Today's reading was a detailed outline of how the human body interacts with various stimuli and motor functions. The overall point the reading seemed to have is that when designing something for people to use you must keep these limitations in mind, such as the example of the varying keyboard designs and how extensive research went into seeing which configurations were easiest for people to type quickly on. Another good example was the physical limitations of using the pocket calculator with one hand. That example can translate directly to mobile application development, as you do not want your user's experience to be hindered by awkward UI placement that requires long reaching with the fingers/thumbs.

Kyle Tanczos 5:21:00 2/6/2014

I thought todays readings were very interesting. It talks about the Model Human Processor, essentially a way of looking at the brain as a compartmental system of inter-working components. They explain the brain's neurological processes as a communication of systems working together. The reason why the readings are interesting is that the way the readings approach brain function is that of a computer system. In real life, scientists are still trying to determine the very low-level functionality of the inner brain: how every area of the brain is responsible for different tasks. This reading tries to account for the area of unknown by describing the brain as a component system.

Bret Gourdie 6:29:03 2/6/2014

This reading discusses the notion of the human processor. It purports to almost benchmark the human body and its performance, something that sounds a bit scary in today's technologically-inclined world. A lot of time is spent discussing memory; with a simple trick, a string of binary numbers becomes easily remembered as a short sequence of decimal numbers. There is also talk of perception, that which would the human detecting that something caused another. This is useful for establishing the "why" of something happening; stimuli without reason is plain confusing and usually does not benefit the user. There is also a section on learning, mostly upon which discussions of remembering lists occur. In summation, this section of the book attempts to present a human as a predictable machine, something with metrics that we can scale our applications off of. IT's a scary thing, really, to think of them as such impersonal beings, but I feel that many a computer scientist would appreciate this perspective every so often.

Zach Sadler 6:37:41 2/6/2014

I found it very interesting how mathematical and scientific today's reading was. The whole article read as an informative study of the properties of the human body, which is something you don't really expect to read in a computer science course. As I was reading I wondered if these statistics are true for humans throughout the last few decades or if computers have adjusted human ability to perform these tasks. Certainly reading is not a task that everyone could do in the past, but visual perception must have improved since the advent of computers. A lot of the paper was a bit too technical to really derive much value from, but the overall message was great to learn.

Pedro Alvillar 7:51:10 2/6/2014

The model human processor is composed of : a set of memories and processors, and a set fop principles of operation. The model human processor is divided into the perceptual system, the motor system, and the cognitive system. Each of these systems has separate processors and memories. The perceptual system handles how the physical world is perceived through the body’s sensory systems. The perceptual system’s memories are stored either in the visual image store or the auditory image store.The visual image store expires significantly faster than the auditory image store. The processor time of the perceptual processor depends inversely on the level of intensity of the stimulus. The motor system, as its name implies, deals with the activation of muscles which enable movement. The motor processor can issue instructions ,on average, about once every seventy milliseconds. The cognitive system includes two memories : working memory, and long-term memory. As it is expected, working memory can become long-term memory, and whatever is learned can’t directly become long-term memory, but a fraction of working memory has a certain probability of becoming long-term memory. Said model of the human processor isn’t definite as there exist many alternatives, however this doesn’t take away from this model’s benefit or credibility, as it provides a good approximation as to how the human processor is laid out.

Charlie Koch 8:14:00 2/6/2014

I found the reading to be very interesting, but some of it seemed needlessly complicated. I understand they are trying to present human though processes and human action and reaction into computer terms and scientific data, but a lot of it seems like things that are common sense. The major points the text orbited around were memory decay, accuracy of memory and physical movement, and reaction times. These seem like very obvious shortcomings of human beings, and any designer in any field should be well aware of these things. The depth to which the text explains and reports findings on these thing is indeed very insightful and can help to design effective interfaces. I will no doubt use some of these things in this class and beyond. I wonder though, has some of this data changed since this book was written? Has the saturation of technology affected how we retrieve, process, store information?

Ryan Ulanowicz 8:25:55 2/6/2014

This reading had to deal with the Human Information Processes and how people use their senses to deal with stimuli and then how they use that information. First we are presented with the way that memory fades, both in visual and auditory memory. Visual memory fades more quickly than auditory because auditory memories must be processed over time. This time that with which memory fades with a unit called the unit impulse response. The motor system is best illustrated by having a person move a pen back and forth as fast as possible for 5 seconds. It illustrates the cycles of that makes up a full cycles of the motor system. This is each cycle of the pen from one line to another line. Memory is another part of the Human Information Processes. Working memory is short term that chunks things together, most people are able to remember a combination of 9 letters. It usually lasts up to 25 seconds but decays from the start. Long term memory lasts forever but there is an issue with retrieval. It must be associated with something else that helps our brain access it and move it into working memory. This makes long term memory semantic. The difficulty of remembering these things involves the Discrimination Principle, this says that remembering things is proportional to how the cues that exist in the brain.

Derrick Ward 8:28:31 2/6/2014

In today's reading we discuss how humans process information. We start by discussing the Model Human Process. The author tells us this model can be described in two ways. The first way is by a set of memories and processors that work in conjunction with one another. The second way is by a set of principles called the "principles of operation". The author then mentions that elaboration on the first way is simpler than the second. We then proceed to talk about the interacting sub-systems. There are three interacting sub-systems. The first sub-system is the perceptual system. The second is the motor system. Finally; the third sub-system is the cognitive system. What is similar about each of these sub-systems is that they each possess their own memories and processors. The Author then begins to elaborate on each subsystem and the sequence in how they interact with each other. The perceptual system consists of sensors and memory buffers. The sensory system outputs information into the visual image store and the auditory image store. The cognitive system receives the symbolically coded information from the image store and uses it in conjunction with information stores in long-term memory to make decisions about how to respond. Lastly, the motor system carries out the response. Then the author begins describing the two types of processors the Model Human Processor switches between, depending on the task at hand. The first is a serial processor. The second is a processor that must perform operations in the three sub-systems in parallel, to the best of its ability. The passage then dives into the very detailed designs of the Perceptual, Cognitive, and Motor System. We discuss Fitts’s Law, Reading Rates, human performance, perceptual causality, as well as other sub-topics. All in all I rather enjoyed this reading, and found it at different points to be challenging.