CS 102 Human-Computer Interaction Lecture 3: Cognition (2) CS102: Monsoon 2015 1
Administrivia Hope you completed the reading assignment Reminder: If you miss a class, you must review the alternate reading within a week to get attendance credit. Also review lecture material (the alternate reading is not a substitute.) Some reference books are held under course reserve in the library CS102: Monsoon 2015 2
Projects Please post in Moodle about project ideas. Do some research and decide teams and rough outline of project by next Monday. Some sources of ideas: Your personal interests/experiences Things to improve campus Scan recent conferences (ACM CHI, UIST or CSCW) Talk to us Be realistic in scoping out the project skills, hardware, test subjects, time, … CS102: Monsoon 2015 3
As we may think CS102: Monsoon 2015 4
As we may think Written in 1945, after 50-60 years of tech. inventions (Electricity distribution, automobiles, airplanes, movies, TV, telephone, atomic bomb…) “[Man] has built a civilization so complex that he needs to mechanize his records more fully if he is to push his experiment to its logical conclusion and not merely become bogged down part way there by overtaxing his limited memory.” CS102: Monsoon 2015 5
Memex “A memex is a device in which an individual stores all his books, records, and communications, and which is mechanized so that it may be consulted with exceeding speed and fl exibility. It is an enlarged intimate supplement to his memory.” What’s in the memex vision that’s not on the web today? CS102: Monsoon 2015 6
CS102: Monsoon 2015 7 http://trevor.smith.name/memex/
L2: Recap CS102: Monsoon 2015 8
Elements of Cognition • Attention • Perception, recognition • Memory • Language, reading, listening, etc. • Problem-solving, decision making, planning, … CS102: Monsoon 2015 9
Transactive memory Externalized memory to other repositories like other people, paper or written materials, tangible objects, etc. 10 CS102: Monsoon 2015
Memory in the Internet age People forget items they think will be stored on a computer, and remember those they think will not available. Participants asked to enter trivia facts under 2 conditions: they were told it would be either saved or erased Mean recall in “erase” condition: 31% vs. “save” condition: 22% Google e ff ects on memory: Cognitive consequences... CS102: Monsoon 2015 11
Memory in the Internet age If people know where to fi nd information, they are less likely to remember it Participants asked to enter trivia facts and shown one of 3 messages: “erased”, “saved”, “saved in folder X” Mean correct answer to true/false question: 93% (erased), 88% (saved), 85% (saved to a folder) Google e ff ects on memory: Cognitive consequences... CS102: Monsoon 2015 12
Memory in the Internet age People are primed to turn to the Internet when faced with gaps in knowledge Demonstrated with a modi fi ed Stroop test Google e ff ects on memory: Cognitive consequences... CS102: Monsoon 2015 13
Stroop testing Invented by J.R. Stroop in 1935 Uses interference as a way to study access A more accessible word will cause more interference Test interference by asking people to name the color a word is written in Studies of interference in serial verbal reactions CS102: Monsoon 2015 14
Stroop testing: let’s try it http://cognitivefun.net/test/2 Studies of interference in serial verbal reactions CS102: Monsoon 2015 15
Memory in the Internet age Comparing interference of (e.g.) Google/Yahoo to Nike/ Target Mean 712 ms vs. 591 ms after hard questions Mean 603 ms vs. 559 ms after easy questions Google e ff ects on memory: Cognitive consequences... CS102: Monsoon 2015 16
Memory in the Internet age “We are becoming symbiotic with our computer tools, growing into interconnected systems that remember less by knowing information than by knowing where the information can be found.” https://www.youtube.com/watch?v=ihgXRWaIlVE CS102: Monsoon 2015 17
Augmenting Cognition 18 CS102: Monsoon 2015
Scanning a web page CS102: Monsoon 2015 19
Using personal history Email history 101010 011010 100101 010101 011101 010100 101010 101010 101010 010101 010101 001010 010010 100101 0000# CS102: Monsoon 2015 20
Experience-infused browser CS102: Monsoon 2015 21
Experience-infused browser CS102: Monsoon 2015 22
Experience-infused browser CS102: Monsoon 2015 23
Experience-infused browser The browser is like a second brain with unlimited capacity, and responds within a few seconds. Provides simple, private personalization of web pages CS102: Monsoon 2015 24
Memory Testing 25 CS102: Monsoon 2015
The memory problem 3.8M patients in U.S. have Alzheimer’s, 5.4M MCI Cost of dementia expected to exceed cancer or heart disease by 2030 Current ways of testing memory are basic CS102: Monsoon 2015 26
CELL: Cognitive Evaluation with Life-Logs • Use digital life-logs to establish ground truth for memory tests • Automatically generate questions from sent email • If successful, much more accurate and inexpensive way of testing CS102: Monsoon 2015 27
CELL research issues Do older people remember less? (How) does memory drop o ff over time? Are more frequently mentioned items better remembered? Are people names better remembered than other names? etc… CS102: Monsoon 2015 28
Example CELL question CS102: Monsoon 2015 29
Location History http://google.com/locationhistory CS102: Monsoon 2015 30
Cognitive biases Judgment under Uncertainty: Heuristics and Biases 31 CS102: Monsoon 2015 Psychology of Intelligence Analysis
Cognitive biases 3 (major) types • Representativeness • Availability • Anchoring and adjustment CS102: Monsoon 2015 32
Representativeness 70% of people are engineers and 30% are lawyers. "Dick is a 30-year old man. He is married with no children. A man of high ability and high motivation, he promises to be quite successful in his fi eld.” Judge: Is Dick a lawyer or an engineer? Leads to base-rate fallacy CS102: Monsoon 2015 33
Misconceptions of chance A fair coin is tossed 6 times. Judge: Which one is more likely? T H T H H T H H H H H H CS102: Monsoon 2015 34
E ff ect of sample size 2 hospitals: • 15 children born per day • 45 children born per day Babies are 50% boys, 50% girls (on avg.) Judge: Which hospital (if any) is more likely to have days where > 60% children born are boys? CS102: Monsoon 2015 35
E ff ect of sample size Consider the di ff erence between avg. word length of: (a) successive pages (b) successive lines Which varies more? CS102: Monsoon 2015 36
Regression to the mean An extreme instance will likely be followed by an instance that is less so. For example, after a really bad performance, a better one is likely to follow, and after a really good performance, a worse one is likely to follow. CS102: Monsoon 2015 37
Causal explanations We bias towards causal explanations But in reality, cause may be due to regression to the mean, external, or not explicitly intended We bias towards estimating similar sizes of cause and e ff ect Intuitive to bang on the elevator buttons to summon it faster A tennis star’s career simply peters out We overestimate the role of internal factors and underestimate the role of external factors CS102: Monsoon 2015 38
Oversensitivity to Consistency Unwarranted generalizations from small sample sizes, e.g. The train is always late… Russians are generally…. CS102: Monsoon 2015 39
Availability bias In the dictionary, does ‘r’ appear more often as the fi rst letter or the third letter? How many ways to pick 2 members out of 10 vs. 8 members out of 10? CS102: Monsoon 2015 40
Vividness criterion Vivid cases outweigh a much larger body of statistical evidence “Man-who syndrome”, e.g. I know a man who had cancer… I know a man who ran the ultra-marathon… Leads to an over-estimate of the actual probability CS102: Monsoon 2015 41
Out of sight, out of mind Corollary: People fail to correct for lack of information “The average person eats 3 pizzas a year” Immediacy e ff ect: “This is the best movie I’ve ever watched.” “Yesterday was a historic moment!” CS102: Monsoon 2015 42
Anchoring and adjustment Estimate 1 x 2 x 3 x 4 x 5 x 6 x 7 x 8 8 x 7 x 6 x 5 x 4 x 3 x 2 x 1 In studies, median judgement was 512 vs 2250 Adjustments are usually not enough CS102: Monsoon 2015 43
Anchoring and adjustment Discredited evidence persists even after it is debunked e.g. “academic urban legend” of decimal point error about the iron content of spinach CS102: Monsoon 2015 44 http://sss.sagepub.com/content/44/4/638.full.pdf+html
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