Theresa Pittappilly

1
Cognition in Interface Design

• Theresa Pittappilly

2
What is Cognition?

• Process of awareness and thought
• Experimental Cognition
• A state of mind in which we perceive, act, and
  react to events around us effectively and
  effortlessly -e.g. reading a book, having a
  conversation
• Reflective Cognition
• Involves thinking, comparing and decision-making.
  This leads to new ideas and creativity e.g.
  designing, learning and writing a book.

3
What is Cognition?

• Can be described in terms of specific kinds of
  processes
• Attention
• Perception and recognition
• Memory
• Learning
• Reading, speaking and listening
• Problem-solving, planning, reasoning,
  decision-making

4
What is Cognition?

• Attention Process of selecting things to
  concentrate on, at a point in time from the range
  of possibilities available.
• Information presentation is vital. For example
  there is a tendency to use lots of color, sound
  and graphics that can be distracting.
• Good example www.google.com
• Bad example http//www.havenworks.com/

5
What is Cognition?

• Perception Refers to how information is
  acquired from the environment via the different
  senses and transformed into experiences of
  objects, events, sounds and tastes (Roth, 1986).
• For example icons and graphics should enable
  users to readily distinguish meaning.
• Bad example http//www.youtube.com/watch?vw_TgB
  JEHTuQ

6
What is Cognition?

• Memory Involves recalling various kinds of
  knowledge that allow us to act appropriately.
• A filtering process takes place to figure out
  what gets further processed and memorized.
• People are better at recognition than recall.
  Certain kinds of information are easier to
  recognize than others (e.g. pictures)
• Rather than having users memorize command names,
  GUIs provide visually-based options that users
  can browse though till they find what theyre
  looking for.

7
What is Cognition?

• Learning How people use computer-based
  applications.
• People find it easier to learn through doing
  than by following an instruction manual.
• GUIs are good environments for supporting active
  learning. They provide users with explanatory
  support as well as allowing users to undo their
  actions.

8
What is Cognition?

• Reading, speaking and listening These are three
  forms of language processing. The meaning of
  phrases is the same regardless of the mode with
  which it is conveyed.
• The ease of using these different processes
  depends on the person, task and context.
• For example you may need to allow the size of
  text to be increases without affecting the
  formatting.
• Keep the length of speech-based menus to a
  minimum.

9
What is Cognition?

• Problem-solving, planning, reasoning and
  decision-making These involve reflective
  cognition, which includes thinking about what to
  do, what the options are, and what the
  consequences will be.
• For example provide simple and memorable
  functions to aid in the above processes. Good
  example www.cheapflights.com

10
Analytical Evaluation

• Inspections e.g. Heuristic evaluation
• Predictive Models - GOMS

11
Analytical Evaluation

• Heuristic Evaluations A set of usability
  principles used by experts to evaluate
  user-interface elements. Tailored to different
  interactive products. Developed by Jacob Nielsen.
• Visibility of systems
• Match between the system and the real world
• User control and freedom
• Consistency and standards
• Error prevention

12
Analytical Evaluation

• Heuristic Evaluations (continued)
• Recognition rather than recall
• Flexibility and efficiency of use
• Aesthetic and minimalist design
• Help users recognize, diagnose and recover from
  errors
• Help and documentation
• 3-5 evaluators are recommended.

13
Analytical Evaluation

• GOMS Used to model the knowledge and cognitive
  processes involved when users interact with
  systems. It stands for
• Goals The state the user wants to achieve
• Operator Cognitive processes and physical
  actions that need to be performed
• Methods Learned procedures for accomplishing
  the goal.
• Selection rules To determine which method to
  select when they are multiple for a given task.

14
Analytical Evaluation

• GOMS (continued)
• Advantage Allows comparative analyses to be
  performed for different interfaces relatively
  easily.
• Disadvantage Scope. It can only model tasks
  that involve a small set of highly routine tasks.
  It only predicts expert performance does not
  allow for errors to be modeled.

15
Analytical Evaluation

• Other inspections models
• Cognitive walkthrough
• Paper prototype
• The keystroke level model
• Fitts Law

16

• Thank you!