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Pulling it all together, (starting to) the firstseveral chapters of IST331

Frank E. Ritter

For IST 331: The user14 October 2008

ritter@ist.psu.edu

Book Readings: (185 p)APA Sparc Chart (3)ABCS (~180)

Preface1, 2 Appendix 1 & 3 (example)3, 4, 5, 6, 7, 811 (optional)

Other Readings: (108 p)Example exams (10)Kegworth, wikipedia (3)Spink & Cole (21)Barnes et al. (17)Byrne et al. (8)Ritter & Schooler (12)Dawes (34)

Other knowledge:

•Labs•(example labs)•Any optional readings

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How to study

Read all the materials Finish drafting the labs Study previous examsWrite out answers to previous exams Score answers

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QUIZ

What are the 5 most important topics?What are the 5 most important readings?What is the best question to put on the

exam?

(10 min.)

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One way to summarize the material

Anthropometric approach (Can it be used?)

Behavioural approach (How is it used?)

Cognitive Approach(How do they think they are using it?)

Social issues (How about others when usingit?)

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Another way tosummarize: Theories

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Another way to summarise theMaterial: ACT-R or other theory

From Pipedream, Animusic

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Another way to summarize Material

Fitting the user to the machine vs. ….Name those ways

Fitting the machine to the userName those ways

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Another Way to Summarise:Potential Causes of Errors

Single operator's noisy, imperfect humanhardware

Distractions State misidentifcations, not in KS… You should be able to list many more:

perception, action, cognition, social, learning,etc.

Experts catch them Social status vs. task problems, pardon me sir,

but is that not an iceberg?

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Another way to summarise: Fixes for errors

Make movement natural Is the knowledge consistent with previous

knowledge? Is the response consistent with the

stimulus? Set pace appropriately [ruler demo] Is the state of the agents visible to other

agents?

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An answer to many previouslimitations: Learning

Generally follows a powerlaw T=N -alpha

So big speed up initially Lesser speed ups with time Performance time does not follow user’s

description of it Users don't like being on fast slope (but for

games) Changes in strategies put onto a new curve,

typically with different intercept Knowledge to skill to automatic What kinds of learning occur?

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An answer to many previouslimitations: Expertise

About 10 years for world class Less for local/national classRequires deliberate practice Interesting to peopleGreater memory/attention/

vision/knowledge/anticipation Prone to overconfidence, if anything

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An answer to many previouslimitations: Problem solving

When not an expert, or a casual user or alearner

Task/action mappings help

Has to be performed with Input/Outputtools (eg eyes/hands) you now know

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Part of the problem: Known ProblemSolving and reasoning Biases

Plausibility is over done(it must be this error!)

Prototypes can mislead(programmer and is activein the feminist movement)

Relative ratios often overlookedRegression to the mean/sample sizesRestaurants are not as good the second time

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Problems II with problem solving

Single bad experiences cannot begeneralized from

Then confirmation biasRetrieval and perceptual fluency biasLocality and knowledge: Ireland/Indonesia

Based on mental modelsWhich are often naïve and wrongLearn to live with them in your usersThermostats' speed

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Gold Standard

Know your userABCS

Know their tasks Then: Support their tasks with

appropriate design and technology

DO NOT: run a checklistDO NOT: look at interface and opine

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What has not been done for thisreview

Chapter 1 covers…..Chapter 2 covers…..Chapter 3 covers…..Chapter 4 covers…..Chapter 5 covers…..

Theory says: you should do this(and chapters do this too)

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Some Generalities of HumanBehavior

People have abilitities and limitations ofhow well they can work, by hardwareand software

People learn People make errors Performance varies across time and

individuals: so, distribution ofperformance makes more sense