hci chap. 1 thinking & emotion

Thinking & Emotion

김주환

Reasoning Deduction, Induction, Abduction

Problem solving Gestalt Theory, Problem Space Theory, Analogy, Skill Acquisition

Thinking

Deductive Reasoning

• Derive logically necessary conclusion from given premises

If it is Friday then she will go to work It is Friday > Therefore she will go to work.

• Not necessarily to be true

If it is raining then the ground is dry It is raining > Therefore the ground is dry

• Often Misapplied... Some people are babies Some babies cry >> Some people cry ???

Invalid deduction, Not told that all babies are people. Truth and validity clash.

• People bring their world knowledge into the reasoning process.

Deductive Reasoning (cont.)

Inductive Reasoning

• Generalizing case not seen from cases seen e.g. All elephants we have seen have trunks

therefore all elephants have trunks.

• Unreliable and cannot be proved to be true; it

can only be proved to be false … but useful!

Wason's cards

Which cards would you need to pick up to test the truth of the statement?

If a card has a vowel on one side it has an even number on the other.

7 E 4 K

Abductive Reasoning

• Derive explanations for the events we observe e.g. Sam drives fast when drunk. If I see Sam driving fast, assume drunk.

• Unreliable – Not always true – People do infer explanations in this way, and

hold onto them until evidence to support an alternative (often result in confusion & error)

Problem Solving

• Process of finding a solution to an unfamiliar task, using the knowledge we have

• Gestalt Theory, Problem Space Theory, Analogy, Skill Acquisition

Problem Solving : Gestalt Theory

• Problem Solving is both productive and reproductive

• Reproductive draws on previous experience

• Productive involves insight and restructuring of the problem

• Not provide sufficient evidence or structure to support its theories

Problem Solving : Problem Space Theory

• Generating problem states(initial, goal) using legal state transition.

• In means–ends analysis the initial state is compared with the goal state and an operator chosen to reduce the difference between the two.

• Experience allows us to solve problems more easily since we can structure the problem space appropriately and choose operators efficiently.

• In General Problem Solver model the problems may be unfamiliar but the knowledge that is required to solve them is present in the statement of the problem and the expected solution is clear. (Solving Puzzles)

Problem Solving : Analogy

• Analogical Mapping

Mapping knowledge relating to a similar known domain to the new problem

• People often miss analogous information, unless it is semantically close to the problem domain

Problem Solving : Skill Acquisition

• Expert chunked the problem space in order to hold it in short-term memory. Larger chunk holds more information.

• Grouping the problems Novice >> Superficial Expert >> Conceptual

• Anderson's ACT Model

1. Uses knowledge extensively 2. Relies upon known procedures 3. Represents skilled behavior

• Experts tend to rehearse their actions mentally. Efficient

but cause errors when the context changes.

Errors and mental models

• Errors result from changes in the context of skilled behavior (slip)

• Mental model – Based on superstition rather than evidence – Incorrect interpretation of the evidence – Certain universal convention to interpret the

world. If it is violated, explicit support must be given to correct mental model

– Incorrect modeling result in error (mistake)

Emotion

• Various theories of how emotion works – James-Lange: Emotion was interpretation of a

physiological response

– Cannon: Emotional response is more then a recognition of physiological changes

– Schacter-Singer: Emotion results from a person evaluating physical responses in the light of the whole situation

• Emotion clearly involves both cognitive and

physical responses to stimuli

Emotion (cont.)

• Affect – Biological response to physical stimuli – Changes the way we deal with different situations – positive → creative problem solving – negative → narrow thinking

“Negative affect can make it harder to do even easy tasks; positive affect can make it easier to do difficult tasks”

(Donald Norman)

Emotion (cont.)

• Implications of emotion for design – stress : less able to cope with managing

difficult interfaces – relaxed : more forgiving of limitations in the

design

• Design good interfaces – Build interfaces that promote positive

responses; for example by using aesthetics or reward