Understanding Users: Applying Cognitive Psychology to Interaction Design

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Understanding Users Applying Cognitive
Psychology to Interaction Design

• CDMM06 Lecture 3

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Learning Outcomes

• The role of Cognitive psychology in interactive
  systems design
• The importance of cognitive processes of
  Attention, Perception, Memory and Mental Models
  to the design of interactive systems
• Criticisms of the cognitive approach

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What is Cognitive Psychology?

• Branch of psychology that deals with the
  theories, models and experimental investigations
  of mental phenomena.
• High level and low level processes
• Memory
• Perception
• Attention

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How can it be used in design?

• An understanding of users cognitive
  limitations/abilities can
• Inform the design of technologies that Extend
  what people can do and
• Mitigate for their weaknesses

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Normans Two fold Classification

• Experiential
• Active and reactive
• Reading an article
• Driving a car
• Having a conversation
• Giving a lecture

• Reflective
• Creative
• Thinking
• Comparing alternatives
• Decision making
• Writing a lecture

Norman (1993) Things that make us Smart
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Cognitive Psychology Topics

• Attention
• Perception
• Memory
• Learning
• Reading
• Problem Solving

Revising for CDMM06 TCT
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Memory

• At a base level memory involves the recall
  different types of knowledge that allows us to
  act in the world.
• Long term memory
• Working memory
• Spatial memory
• Physical memory

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Memory

• Long term memory
• Stores all the knowledge we have gained about the
  world as concepts, facts and episodes
• Working memory
• Workspace for conscious thought.
• Both under Implicit and Explicit Control
• Recognition is easier than recall

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Working Memory
OK, left on 4th, right on 9th, through 5th Ave,
left on 12th, right on 21st, end of Lonely Street.
How do I get to Heart Break Hotel?
Working memory - memorize directions while
driving your car.
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Working Memory Issues

• Has a limited capacity - Miller (1956)
• Magic Number 7 ( or - 2) items or chunks
• Only one thought can be followed at a time
• Consequence Cognitive Overload

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How has this been Applied?
How has this been Misapplied?

• Have only 7 options on a menu
• Display only 7 icons on a menu bar
• Never have more than 7 bullets in a list
• Place only 7 tabs at the top of a website
• Place only 7 items on a pull-down menu

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Spatial Memory

• Spatial Memory
• Mandler 1977, have shown that people encode the
  spatial location of objects in addition to object
  name and specific characteristics.
• This encoding appears to be effortless and to
  occur implicitly.

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Application of Spatial Memory

• Do not reposition navigation bars from one page
  to the next
• Do not re-order the buttons on a web page

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Focused Application
Robertson, Czerwinski and Larson (2000) designed
a system for the management of bookmarks called
Data Mountain.
Users memory for the location of those pages on
the plane offered reliable advantages over
standard bookmark interface.
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Episodic Memory

• Events are the basic unit of storage, and the
  temporal relationships between them is the basis
  of their organisation in memory, and they way
  they may be retrieved. (Tulving 1983)
• Retrieval cues for episodic memory must relate to
  the time and place at which the memory occurred.

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Applications ofEpisodic Memory

• Bookmarks (Abrams, et al, 1998)
• Organised as a chronological list of episodes
  that provides information about what users have
  been doing over a number of browsing sessions.
• Image Browsing (Winograd, et al 2002)
• Organising images for browsing by the events at
  which they were taken

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Memory General Design Implications

• Do not overload the users memory by requiring
  them to remember complicated procedures
• Design interfaces that promote recognition via
  use of menus, icons and consistency in object
  placement
• Remember to Chunk information

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Attention

• Focusing mental resources on a task or object
• Visual
• Auditory
• Failures in attention are often cited as the main
  cause of accidents.
• Reduces through practice
• Attention shifts can be overt intentional and
  covert- unintentional
• Attention process is mediated by
• Goal Clarity
• Information salience

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Perception

• How information is acquired from the environment
  through sense organs and transformed into
  meaningful information
• Variety of low level processes
• High level processed of Perceptual Organisation

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Perception Design Implications

• Icons and buttons should enable users to
  distinguish their meaning easily
• Text should be legible and distinguishable from
  the background
• Sounds should be audible and distinguishable

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Gestalt Psychology

• Laws of Perceptual Organization
• Describe the way in which people tend to group
  objects together.
• Has direct implications for page layout.

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Similarity
x o x o x o x o x o x o x o x o x o x o x o x o
x x x x x x x x x x x x x x x x x x x x x x x x
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Proximity
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Getting Proximity Wrong!
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(No Transcript)
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Good Continuation
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Continuation in Design
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Familiarity
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Gestalt Used
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Gestalt gone wrong
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Implications

• People may
• Assume that items that look alike to the same
  thing. e.g blue text might be assumed to be
  links.
• Assume that items that are positioned close
  together are related separate regions out.
• May not follow sharp edges or jagged positioning
  of items
• Look for familiar items

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General Implications

• Important to consider what people can do and how
  they will perceptually organise your site.
• WHY?
• Because they will engage in this process
  unconsciously. Whether you like it or not!

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Examples in Design

• Colin Ware et al (2000)
• Interested in developing a usable 3D graphical
  data visualisation which enabled users to
  interact with 3D stereoscopically displays.
• Notoriously difficult application area.
• Approached the problem by studying the perceptual
  factors involved in stereoscopic depth perception
  
• Acknowledging that individuals would vary in
  terms of the development of these perceptual
  skills.
• The resultant interface accommodated for common
  perceptual problems
• Received highly favourable results in usability
  tests.

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The Experimental Method

• Primary application user testing
• Research Evaluations
• Experiments work best in a controlled environment
  
• Extraneous variables
• Confounding variables

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Criticisms of the Cognitive Approach

• Physical and social contexts of people are
  important.
• Are usually directed at single user interaction
• Ignores emotional responses

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Summary

• There is a focus on the individual
• Cognitive factors are interdependent
• Individuals differ in the extent to which they
  possess different cognitive abilities

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Suggested Reading

• Norman D (1988) The psychology of everyday things
• All HCI texts have a chapter on Cognitive
  Psychology
• Key Paper Czerwinski and Larson Cognition and
  the web (link on module website)