Understanding UsersCognition & Cognitive

FrameworksDr. Dania Bilal

IS 588

Spring 2008

Cognition

• What goes on in our minds when carrying out activities

• Involves cognitive processes– Attention– Perception and recognition– Memory– Learning– Reading, speaking, listening– Decision-making, problem-solving, reasoning,

planning, making analogies

Attention

• Involves– auditory and/or – visual senses

• Ease and difficulty of attention depends on– Whether we have goals

• Based information to look for, time involved– Will drive browsing, scanning or – Searching, asking friends

Attention

– Whether information presented/displayed is easy to understand and manipulate

• Dense vs. simple screens• Visual cues used and appropriateness• Spacing, bordering, fonts• Instructions to carry out tasks

• See Text, fig. 3.2, p. 96.

Attention: Design Implications

• Make information salient • Use graphics, color, animation, ordering of

items, spacing, sequencing of information.• Avoid cluttering interface• Use commonly used metaphors• Use fill-ins as appropriate• Use meaningful icons• See p.101 for additional design for attention

Memory

• Allows recalling knowledge• Humans can’t recall everything they store

in their memories• Filtering process is used to decide on

information to process and memorize– Information is encoded into the brain and

retrieved based on context in which it is encoded

Cognition

• Recognition is easier than recall

• GUIs supports recognition

• Web browsers support recognition

• Command-driven and DOS-based systems don’t support recognition– Why?

• George Miller’s theory: 7+or -2

Memory

• Supporting recall– Design based on familiarity– Design based on mnemonics– Design based on context or relevance of

information to user• Example: what’s the name of your first significant

other? Used to authenticate a user’s forgotten password.

• See also text, p. 110 for design implications

Reading, Speaking, Listening

• Depends on ease with which people can read, speak, and listen

• Reading can be quicker than speaking or listening

• Listening requires less cognitive effort than reading or speaking

• Preference of listening vs. reading depends on person’s cognitive ability

• Design Implications: Text, p. 114.

Cognitive Frameworks

• Represent and predict user behavior

• Have impact on interaction design– Mental models– Theory of action– Information processing– External cognition– Distributed cognition

Mental Models

• Knowledge people have of how to interact with a system and how the system works

• The more people learn about a system and how it functions, the more their mental models develop.

Question: Why do people use erroneous or incomplete or inaccurate mental models when interacting with a system?

Mental Models

• Most people have poor mental models of how the Internet, search engines, and other computer-based technologies work.

• Norman (83): users mental models are often incomplete, easily confusable, based on inappropriate analogies, and superstition.– They find it difficult to identify, describe, or

solve a problem, and lack the words or concepts to explain what’s happening.

Mental Models

• What is needed of users to do about their mental models?

• How should interaction designers address these problems in designing systems?

Students: Discuss these questions in relation to:– User’s role– System designer’s role

Theory of Action

• Norman (1986) specifies 7 stages of an activities based on theory of action.

• Establish a goal• Form an intention• Specify action or sequence• Execute action• Perceive the system state• Interpret the state• Evaluate the system state vis-à-vis goal and

intention

Theory of Action

• Students: Use the stages of this theory and apply it to an activity for interacting with a Web engine. – How do the stages apply to your activity?– Are they linear or non-linear based on your

activity?– What’s wrong with this theory?

Theory of Action

• Core concepts– Gulf of execution– Gulf of evaluation

• Best represented in the figure showing how these two gulfs can be bridged (text, p. 121).

• Roles of designers and users in bridging the gulfs to reduce cognitive effort required to complete a task.

Information Processing

• Human mind as an information processor• Information enters and exit the mind through a

series of ordered processing stages.– See Text, fig. 3.11, p. 123.– Approach is based on modeling mental activities that

happen exclusively in the head.

Students: Provide comments about the model.

Alternative approach to Information processing model

• Study of cognitive activities in the context in which they occur, analyzing cognition as it happens.

• Focus on environment and how certain structures can aid cognition and reduce cognitive load

Reducing cognitive load

Externalizing cognition– Externalizing to reduce memory load

• Use external representations (e.g., notes, diaries, lists, and other external reminders)

– Computational offloading• Use of a tool in conjunction with external reminders (e.g.,

use a calculator to solve a mathematical problem)

– Annotating and cognitive tracing• Modify representations to reflect changes that occurred

(e.g., crossing off or underlining completed tasks on a list)