COM 3210, Week 6

Making sense from prior experience

Topics

Types of reasoning that users engage in

Learning theoriesLearning modelsConclusions for interface design

1. Reasoning

Two types of reasoning:Based on analogies Based on metaphors

Analogy and Metaphor

An analogy provides an explicit, isomorphic mapping between objects of two domains

A metaphor is a looser connection that draws on similarities, but also includes dissimilarities.

Examples

Killing a tumor is like a general’s army attacking a fortress surrounded by mines

Your PC’s operating systems works like a desktop

whether something is an analogy or a metaphor also depends on the scope of the comparison

Computing metaphors

No chance for real analogies in computingcomputing metaphors use real world

objects in a computing environmentthey provide an intuitive understanding of

the computing object and initiate a process of active learning

computer metaphors are indispensable as overarching design strategies, but choose carefully

The desktop metaphor

Pictures of trash can Macintosh

The desktop metaphor “The use of the trash can to eject a disk was present form

the very beginning of the Macintosh interface. […] The original Mac had not hard disk. […] Because most users typically would switch back and forth between several diskettes during a session, it was deemed appropriate for the Mac to keep a memory image of the list of files of the various disks, regardless whether or not the diskette was actually inserted in the drive. […] Often, during the course of a session, the user would finish using a particular diskette, […] To reclaim vluable space, the now unwanted list of files represented by the grayed-out icon could be thrown away by dragging it into the trash…”

Tom Erickson, Apple

2. Learning Theories

Major groups:behaviorist theories constructivist theories

Behaviorist theories

Learning as changes of observable external behavior

Stimulus - response, selective reinforcement

habitsProminent Behaviorist: SkinnerLearning as a reactive process

Constructivist theories

Learning as constructing meaning in one’s mind

building of conceptual structures through reflection and abstraction

not directly observablerequires self regulationlearning as an active processPiaget, Gestalt

Constructivist approaches

PerceptionOrganizationDecision makingProblem solvingAttention Memory

3. Some practical learning models

concept formationlearning by explorationlearning by explanationlearning by imitationlearning by chunkingproceduralization

Concept formation

Common response to a class of stimulidiscrimination of distinctive features of

objectsconjunctive: Car - 4 wheels and enginedisjunctive: meazels - one or several of the

following symptoms: relational: rectangle - four sided object

with the two opposite sides of the same length

Concept formation

Users acquire new concepts and refine them

e.g. Children learn about dogs and cats

first concept: animals have four legs (humans have two)

refinement: birds are animals and have only two legs.

Concept formation

What kind of concept does a computer user need to learn?

How can designers support concept formation

Learning by experimentation

Learning as an active processexploration and experimentation:

“Learning by doing”experiential learning theory (Gibbs

1988): Concrete experience

Reflective observation

Abstract conceptualization

Active experimentation

Learning by experimentation

How can designers facilitate this kind of learning?

Restricted functionality at firsttraining wheelsfeedbacksafety nets‘undo’

Explanation-based learning

general ideas and supporting facts such that the learning can see the relationship between them

e.g. lecturesmental modelsWhat are sources of explanation for

computer users?What makes a good explanation?

Minimalist instruction

people rather learn by experimentation than by explanation

explanation i.e. instruction should support that

instruction should be as little as possible, but as much as necessary

Minimalist instruction

Focus on real world activities of the task domain

Choose an action oriented approach (how to do things)

emphasize error recognition and recovery

eliminate repetitions, summaries, reviews, and exercises

Learning by imitation

Piaget: three types of human adaptation:

Play: assimilating objects to predetermined activities regardless of the object’s attributes, e.g. using chair as horse

Simple Imitation: change behavior to be something else, e.g. using mam’s lipstick, but also dance lessons

Intelligent Adaptation

Assimilating aspects of the environment to the cognitive structure and

accommodating cognitive structures to the environment

guided by structures and resulting in changed structures

e.g. apprenticeship (crafts), pilot-training, nurse training, learning to drive a car

Immitation and intelligent adaptation

Learning to do things: skillscan start as imitation and may move

on to intelligent adaptationHow can this be exploited in

interface design?How can a designer support this type

of learning?

Learning by chunking

Forming general rules from specific instances

declarative chunking: e.g. grouping digits of a phone number.

Procedural chunking: grouping several actions into a new action, e.g. drag and drop

Proceduralization

From declarative to procedural knowledgefrom facts to how-to-do knowledgefrom knowing everything about

typewriters to learning how to typefrom knowing everything about windows

to learning how to use itConsistency is important, but can be

harmful or annoying

Exercise: answer the following questions

What is the tree that grows from an acorn?What is the black cover garment that one

wraps around one self?What sound does a frog make?“knock knock” stories are a kind of …What’s the term to say you’ve got no

money?What’s the clear part of an egg?

Habit intrusion

Users tend to behave in habitual ways

even if it is not appropriateHow can designers incorporate

habitual behaviour?

4. Design principles for learnability (Dix)Predictability - help users predict future

actionsSynthesizability - help user asses effects

of past actionFamiliarity - help users to apply past

knowledgeGeneralizeability - help users to extend

knowledgeConsistency - similar behavior in similar

situations

Summary week 6

Reasoning by analogy and by metaphorModels of learning:

concept formation experimentation explanation imitation and intelligent adaptation chunking proceduralization

Further reading

Preece, J. et al. (1994) Human Computer Interaction

Eberts, R. (1994) User Interface Design Dix et al. (1998) Human Computer Interaction Carroll, J. (1990) The Nurnberg Funnel MIT Press Carroll, J. (1998) Minimalism: Beyond the

Nurnberg Funnel MIT Press Huthicns, E. (1995) Cognition in the Wild. MIT

Press Gibbs, G. (1988) Learning by Doing