CS 102 Human-Computer Interaction Lecture 2: Cognition (1)

Transcription

1 CS 102 Human-Computer Interaction Lecture 2: Cognition (1) 1

2 Reminders Start your idea-logs Start thinking about projects Post in Moodle forums about your interests and abilities (coding, design, user testing, etc.) before next Monday First reading assignment review due next Monday 4.15pm (via to Recap of Lecture 1 2

3 Elements of Cognition Attention Perception, recognition Memory Language, reading, listening, etc. Problem-solving, decision making, planning, 3

4 Allen Newell and Herb Simon Pioneers in exploring cognition using computers 4

5 Inspiration: human problem solving 5 See Herb Simon's tribute to Allen Newell

6 AI and HCI Many of the HCI founders came from an AI background Their vision was to get a computer to do what a human could, so they studied human cognition deeply Had some success with AI applications in areas like logic, reasoning, proof assistants, game-playing, expert systems, etc. 6

7 High-level interaction models Given an interface, can we predict user performance on some task using a high-level cognitive model? This may tell us which interface might be better at a task without having to build its details 7

8 High-level interaction models GOMS - Goals - Operators - Methods - Selectors Keystroke Level Model (K) Keypress, (P) Point, (H) Home to keyboard, (D) Draw line 8

9 Model Human Processor 9 Card, Moran, Newell, 1983

10 High-level interaction models Generally for expert users May have to be calibrated for specific operations May be useful for back-of-the-envelope comparison But they ve seen limited real-world use 10

11 Perception 11

12 Perception rexarxabxy ix is xosxibxe tx rexlaxe exerx thxrd xetxer xf a xenxenxe wxth xn x xnd xou xtixl cxn mxnaxe tx rexd ix wixh sxme xifxicxlty. We perceive what we expect 12

13 Perception 13

14 Perception Perceptions are resistant to change 14

15 Perception fixation Bruner-Potter experiment showed images of blurred objects slowly coming into focus (1964): 1) At any particular clarity of the image, those who see it for the first time are more likely to recognize the objects correctly than those who started viewing at a less clear stage (reason: fixation on wrong identification) 2) the longer the exposure, the harder it is to correct impressions 15

16 Perceiving incongruities Bruner-Postman experiment with playing cards (1949): Sequences from a set of 4 normal, 6 abnormal cards (suits printed in the opposite color) shown to participants for increasing durations (3 times at 10ms, then 3 times at 30ms, 3 times at 1000ms) until correctly recognized. The average time of recognition of the abnormal cards is more than 4x greater than for normal cards. In fact 10% of abnormal cards were simply not recognized correctly even after all exposures. 16

17 Perception More time for abnormal cards (avg. 28ms vs. 114ms) 10% of abnormal cards not recognized at all! 17

18 Perception Prior experience with abnormal cards helps 18

19 Reactions to abnormal cards Dominance: That must be the red six of hearts Compromise: That s a purple six of hearts Disruption: I don't know what the hell it is Recognition: Good Lord, what have I been saying? That's a red six of spades 19

20 Human Memory 20

21 What are the different kinds of memories? 21

22 Experimental study of memory Herman Ebbinghaus,

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24 Memory Types Episodic vs. Semantic Long-term vs. short-term Working memory, muscle memory Retrospective vs. prospective Spatial, Temporal Transactive 24

25 Memory Types Recognition vs. recall e.g. GUI vs. command line 25

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27 Exercise: Going back in time Write down one thing you remember specifically about each weekend, going back in time. Be sure about the memory; do not refer to anything else. Aug Aug Aug. 8-9 Aug. 1-2 July July July July 4-5 June June June June 6-7 May May May May

28 Discussion How hard was it? How did you work it out? How could you go back further? What if you could go back further? 28

29 Memory in the Internet age 29

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