Lecture 3

1. Lecture 3 Psychology and Human Computer Interaction: Cognitive Processes Tate's HCI

2. Learning Objectives: • Discuss the implications that the limitations in memory and decision-making have on human computer interface design. • Discuss the implication of response time and feedback on performance on human computer interface design. Tate's HCI

3. Content: Cognitive Processes • Memory • Decision-making • Response Time • Feedback on Performance Tate's HCI

4. Cognitive Processes • Cognition is a concept used in different ways by different disciplines, but is generally accepted to mean the process of thought. For example, in psychology and cognitive science it refers to an information processing view of an individual's psychological functions. Other interpretations of the meaning of cognition link it to the development of concepts; individual minds, groups, organizations, and even larger coalitions of entities, can be modeled as societies which cooperate to form concepts. Tate's HCI

5. Memory • ‘Memory’ is a label for a diverse set of cognitive capacities by which humans and perhaps other animals retain information and reconstruct past experiences, usually for present purposes. Our particular abilities to conjure up long-gone episodes of our lives are both familiar and puzzling. We remember experiences and events which are not happening now, so memory seems to differ from perception. Tate's HCI

6. We remember events which really happened, so memory is unlike pure imagination. Memory seems to be a source of knowledge, or perhaps just is retained knowledge. Remembering is often suffused with emotion. It is an essential part of much reasoning. It is connected in obscure ways with dreaming. Some memories are shaped by language, others by imagery. Tate's HCI

7. There are generally three types of memory: sensory memory, short-term memory and long-term memory. Tate's HCI

8. Sensory memory • The sensory memories act as buffers for stimuli received through the senses. A sensory memory exists for each sensory channel: iconic memory for visual stimuli, echoic memory for aural stimuli and haptic memory for touch. Information is passed from sensory memory into short-term memory by attention, thereby filtering the stimuli to only those which are of interest at a given time. Tate's HCI

9. Short-term memory • Short-term memory acts as a scratch-pad for temporary recall of the information under process. For instance, in order to understand this sentence you need to hold in your mind the beginning of the sentence you read the rest. • Short term memory decays rapidly (200 ms.) and also has a limited capacity. Chunking of information can lead to an increase in the short term memory capacity. Tate's HCI

10. Short-term memory • This is the reason why a hyphenated phone number is easier to remember than a single long number. The successful formation of a chunk is known as closure. Interference often causes disturbance in short-term memory retention. This accounts for the desire to complete the tasks held in short term memory as soon as possible. Tate's HCI

11. Long-term memory • Long-term memory is intended for storage of information over a long time. Information from the working memory is transferred to it after a few seconds. Unlike in working memory, there is little decay. Tate's HCI

12. Long-term memory • There are two types of long-term memory: episodic memory and semantic memory. Episodic memory represents our memory of events and experiences in a serial form. It is from this memory that we can reconstruct the actual events that took place at a given point in our lives. Tate's HCI

13. Long-term memory • Semantic memory, on the other end, is a structured record of facts, concepts and skills that we have acquired. The information in semantic memory is derived from that in our own episodic memory, such that we can learn new facts or concepts from our experiences. Tate's HCI

14. Long-term memory structure Tate's HCI

15. Long-term memory processes • There are three main activities related to long term memory: • storage, • deletion and • Retrieval Let’s use the “Study For Exam” example  Tate's HCI

16. Information from short-term memory is stored in long-term memory by rehearsal. The repeated exposure to a stimulus or the rehearsal of a piece of information transfers it into long-term memory. Experiments also suggest that learning time is most effective if it is distributed over time. Deletion is mainly caused by decay and interference. Emotional factors also affect long-term memory. Tate's HCI

17. However, it is debatable whether we actually ever forget anything or whether it becomes increasingly difficult to access certain items from memory. Having forgotten something may just be caused by not being able to retrieve it ! Information may not be recalled sometimes but may be recognized, or may be recalled only with prompting. This leads us to the third process of memory: information retrieval. Tate's HCI

18. There are two types of information retrieval: recall and recognition. In recall, the information is reproduced from memory. In recognition the presentation of the information provides the knowledge that the information has been seen before. Recognition is of lesser complexity, as the information is provided as a cue. However, the recall can be assisted by the provision of retrieval cues which enable the subject to quickly access the information in memory. Tate's HCI

19. Memory Site: • Here’s a cool site for getting memory tips: • http://www.helpguide.org/life/improving_memory.htm Tate's HCI

20. Decision Making • Decision making can be regarded as an outcome of mental processes (cognitive process) leading to the selection of a course of action among several alternatives. Every decision making process produces a final choice. The output can be an action or an opinion of choice. Tate's HCI

21. Human performance in decision making terms has been the subject of active research from several perspectives. From a psychological perspective, it is necessary to examine individual decisions in the context of a set of needs, preferences an individual has and values they seek. Tate's HCI

22. From a cognitive perspective, the decision making process must be regarded as a continuous process integrated in the interaction with the environment. From a normative perspective, the analysis of individual decisions is concerned with the logic of decision making and rationality and the invariant choice it leads to. Tate's HCI

23. Decision making processes topics • According to behavioralist Isabel Briggs Myers, a person's decision making process depends on a significant degree on their cognitive style. Myers developed a set of four bi-polar dimensions, called the Myers-Briggs Type Indicator (MBTI). Tate's HCI

24. The terminal points on these dimensions are: • thinking and feeling; • extroversion and introversion; • judgment and perception; and • sensing and intuition. She claimed that a person's decision making style is based largely on how they score on these four dimensions. Tate's HCI

25. For example, someone who scored near the thinking, extroversion, sensing, and judgment ends of the dimensions would tend to have a logical, analytical, objective, critical, and empirical decision making style Tate's HCI

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27. Some of the decision making techniques that we use in everyday life include: • listing the advantages and disadvantages of each option, popularized by Plato and Benjamin Franklin • flipping a coin, cutting a deck of playing cards, and other random or coincidence methods • accepting the first option that seems like it might achieve the desired result Tate's HCI

28. prayer, astrology, revelation, or other forms of divination • comply to a person in authority or an "expert" • choosing the alternative with the highest probability-weighted utility for each alternative (you can read up on Decision Analysis) Tate's HCI

29. Response/Reaction Time • Reaction time (RT) is the elapsed time between the presentation of a sensory stimulus and the subsequent behavioural response. RT is often used in experimental psychology to measure the duration of mental operations, known as mental chronometry. The behavioural response is often a button press but can also be an eye movement, a vocal response, or some other observable behaviour. Tate's HCI

30. Types of RT tasks • Simple reaction time is usually defined as the time required for an observer to detect the presence of a stimulus. For example, an observer might be asked to press a button as soon as a light or sound appears. Mean RT is approximately 180 to 200 milliseconds to detect visual stimuli, whereas for sound it is around 140-160 milliseconds. It also depends on the energy level of that instance. Tate's HCI

31. Go/No-Go reaction time tasks require that the observer press a button when one stimulus type appears and withhold a response when other stimulus types appear. For example, the observer is to press the button when a red light appears and not respond when a green light appears. Tate's HCI

32. Choice reaction time tasks require distinct responses for each possible class of stimulus. For example, the observer may be asked to press one button if a red light appears and a different button if a yellow light appears. Tate's HCI

33. Feedback on Performance • Definition of "haptic feedback" • Haptic feedback, often referred to as simply "haptics", is the use of the sense of touch in a user interface design to provide information to a end user. When referring to mobile phones and similar devices, this generally means the use of vibrations from the device's vibration alarm to denote that a touchscreen button has been pressed. Tate's HCI

34. In this particular example, the phone would vibrate slightly in response to the user's activation of an on-screen control, making up for the lack of a normal tactile response that the user would experience when pressing a physical button. The resistive force that some "force feedback" joysticks and video game steering wheels provide is another form of haptic feedback. Tate's HCI

35. How does feedback influence performance? • Feedback facilitates greater interaction with the user and the application with which they are interfacing with. • With the learning curve out of the way, performance will heighten in the time taken to complete a task. The End Tate's HCI