Human Abilities: Vision, Memory and Cognition. Oct 14, 2016

Transcription

1 Human Abilities: Vision, Memory and Cognition Oct 14, 2016

2 Milestone I How many users? Depends Fall 2016 COMP

3 Midterm True or false Multiple choice Short answer Fall 2016 COMP

4 Midterm sample question 1. You are designing an on-the-shoppingcart device that helps people go through the process of grocery shopping for example, to retain a shopping list, and/or provide a map of the store to help people locate items. When you bring up the idea of doing some user research, a co-worker suggests bringing in 5 university students to the office to discuss their shopping habits. i) What are some strengths of this approach (4pts)

5 Terrible answer (1 pt? MAYBE?) talking to users is good

6 Passable answer (2 pts) This approach is good because it gets input from potential users who may have different views than the design team.

7 Good answer (3 pts) This approach is good because it helps the design team to move beyond their own, limited understanding. Getting input from potential users who may have different views can provide new insight that may be otherwise missed.

8 Great answer (4 pts) This approach is good because it helps the design team to move beyond their own, limited understanding. Getting input from potential users who may have different views can provide new insight that may be otherwise missed. Although five people is small, it is enough to provide a rounded view. Also, students may represent a demographic who may need help with shopping, and may need / benefit from this device

9 Questions? Fall 2016 COMP

10 Today Memory Types of memory Capabilities and limitations Types of cognition Fall 2016 COMP

11 Reminder Simplified model of a human Input/output Information is perceived Memory Information is stored Processing Information is processed and applied Fall 2016 COMP

12 Memory, Cognition and Learning Interacting with technology is cognitive Need to take into account cognitive theories in HCI and cognitive limitations of users Provides insight into what users can and cannot be expected to do Helps identify and explain the nature and causes of problems users encounter Fall 2016 COMP

13 Memory Involves encoding & recalling knowledge and acting appropriately We don t remember everything - involves filtering and processing Context is important We are much better at recognition than recall IMPLICATION: rise of the GUI over commandline interfaces Better at remembering images than words IMPLICATION: use of icons rather than names Fall 2016 COMP

14 Memory There are 3 types of memory: 1. Sensory 2. Short-term 3. Long-term Fall 2016 COMP

15 Sensory Memory Buffer for stimulus received through senses One buffer for each channel: 1. Iconic memory for visual 2. Echoic memory for aural 3. Haptic memory for touch Very temporary: information constantly over-written/destroyed Implications? Fall 2016 COMP

16 Attention Information is passed from sensory memory to short-term memory through attention Which stimuli we attend to depends on: Arousal Interest Need Fall 2016 COMP

17 Short-Term Memory A.k.a. working memory Acts as a temporary scratch pad for temporary recall Rapid access (~70ms), rapid decay (~200 ms) Interference often causes disturbances in shortterm memory retention This accounts for the desire to complete the tasks held in short-term memory as soon as possible What does this mean for alerts? Fall 2016 COMP

18 Short-Term Memory Limited capacity 7+-2 chunks (Miller, 1956) Chunk: Any meaningful combination of items With good chunking, short-term memory is essentially unlimited E.g. CAT DOG PIG CLOCK (n=4 chunks) ATD OGP IGC LOCKC (n=14 chunks) Fall 2016 COMP

19 Short-Term Memory Inappropriate use of the 7+-2 rule Present only 7 options on a menu Display only 7 icons on a tool bar Have no more than 7 bullets in a list Place only 7 items on a pull down menu Place only 7 tabs on the top of a website page Why? Fall 2016 COMP

20 Long-term memory Long-term store of facts, experiential knowledge, procedures Unlimited capacity Slow access time (~0.1 second) Slow or no decay Information moves from short- to long-term memory through rehearsal Fall 2016 COMP

21 Forms of Long-Term Memory 1. Episodic memory represents our memory of events and experiences in a serial form from this memory we reconstruct the actual events that took place at a given point in our lives 2. Semantic memory: structured record of facts and concepts that we have acquired information is derived from that in our own episodic memory, such that we can learn new facts or concepts from our experiences Fall 2016 COMP

22 Long-term memory What helps us remember? Meaning New information can be added to existing memory structures Categories Pictures Cues to assist with recall should be provided during the phase of encoding Recognition much easier than recall Research also suggests that learning time is most effective if it is distributed over time Fall 2016 COMP

23 Long-Term Memory What can cause us to forget? Interference Retroactive interference: New information masks old Proactive inhibition: Old information leaks through Debatable whether we actually ever forget anything or whether it becomes increasingly difficult to access certain items from memory Fall 2016 COMP

24 Long-Term Memory Where is long-term memory important in HCI? Examples Remembering procedures? Websites visited? Files? Fall 2016 COMP

25 Reducing Memory Load Users sometimes have to employ workarounds to reduce memory load E.g., Externalizing information From Fall 2016 COMP

26 Cognition Users have goals Form plans on how to meet those goals Rely on cognitive resources (including memory) Cognition cognitive mental processes; also : a product of these processes (Merriam-Webster Online) Where cognitive is defined as: of, relating to, being, or involving conscious intellectual activity (as thinking, reasoning, or remembering ) Fall 2016 COMP

27 Cognition Cognition occurs at various levels: Conscious Cognition Unconscious Cognition Fall 2016 COMP

28 Conscious Cognition Our focus of attention Serial processor Can attend to only one thing at a time Short-term memory Low bandwidth Limited amount of information that can be processed at a time Fall 2016 COMP

29 Unconscious Cognition Parallel processing Ability to do many things simultaneously Walk and chew gum at same time Higher bandwidth Can process lots of information at same time Think about all the information processed when walking Long-term memory Lots of resources to draw upon Fall 2016 COMP

30 Cognition Property Conscious Unconscious Engaged by Used in Can handle Accepts Operates Controls Capacity Persists for Novelty, emergencies, danger New circumstances Decisions Logical propositions Sequentially Volition Tiny Tenths of seconds Repetition, expected events, safety Routine situations Non-branching tasks Logic or inconsistencies Simultaneously Habits Huge Decades (lifelong) Fall 2016 COMP

31 Learning As we learn new things, they are pushed down from our conscious to unconscious levels of cognition Things become automatic Examples? Fall 2016 COMP

32 Learning Examples Driving a car Initially difficult to coordinate both hands and feet Requires full cognitive attention In time, becomes more or less automatic Can instantly brake, accelerate Typing Initially requires full cognitive attention Over time, pushed down the stack to unconscious levels of cognition Fall 2016 COMP

33 Learning Novel actions must be explicitly guided by conscious effort and feedback Over time, actions become automatic, ballistic Once you start an action, it executes to completion Not under conscious control Not as much feedback required by interface Fall 2016 COMP

34 Example: Writing a Research Paper What is process of writing a paper? On a spectrum, what aspects of it are under conscious, cognitive control, and which are ballistic? Fall 2016 COMP

35 Paper Example Decide on research paper topic Conscious Decide to search a range of databases Conscious Use mouse, keyboard to navigate to online database Motor actions are ballistic What happens if keyboard layout is Dvorak? Fall 2016 COMP

36 Implications for Interfaces We cannot stop habits from forming What are implications for interface design? Fall 2016 COMP

37 Implications for Design Need to be careful what habits we encourage Confirmation dialogs with options in same place will lead to people automatically dismissing them In what situations is this undesirable, and how do designers work around this problem? Consistency and congruency in interfaces help draw upon unconscious cognition Help reduce cognitive effort required for learning Fall 2016 COMP

38 Recap: Memory, Cognition Forms of memory: 1. Sensory memory: High capacity Short duration 2. Short-term memory Low-capacity Fast access Short duration 3. Long-term memory Slow access Large capacity Long duration Fall 2016 COMP

39 Recap: Memory, Cognition Processes that transfer information between stores: Sensory -> short-term: attention Short-term -> long-term: rehearsal, encoding Long-term -> short-term: recall Forms of cognition Unconscious Conscious Fall 2016 COMP