Understanding Users Cognition & Cognitive Frameworks

1. Understanding UsersCognition & Cognitive Frameworks Dr. Dania Bilal IS 588 Spring 2008

2. 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

3. 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

4. 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.

5. 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

6. 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

7. 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

8. 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

9. 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.

10. Cognitive Frameworks • Represent and predict user behavior • Have impact on interaction design • Mental models • Theory of action • Information processing • External cognition • Distributed cognition

11. 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?

12. 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.

13. 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

14. 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

15. 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?

16. 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.

17. 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.

18. 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

19. 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)