Chapter 2 Cognitive Aspects

Cognition

Cognition process

Attention/intention

Perception

Memory

Mental Models

Information Processing

Why need to understand users?

  1. Interacting with technology is cognitive
  1. Need to take into account cognitive processes involved and cognitive limitations of users.
  1. Provides knowledge about what users can and cannot be expected to do
  1. Identifies and explains the nature and causes of problems users encounter
  1. Supply theories, modelling tools, guidance and methods that can lead to the design of better interactive products
  1. Attention
  1. Perception and recognition
  1. Memory
  1. Learning
  1. Reading, speaking and listening
  1. Problem-solving, planning, reasoning and decision-making
  1. Selecting things to concentrate on point in time from the mass of stimuli around us
  1. Allows to focus on information that is relevant to what doing
  1. Involves audio and visual senses
  1. Focussed and divided attention enables us to be selective in terms of the mass of competing stimuli but limits our ability to keep track of all events.
  1. Information at the interface should be structured to capture attention eg: colour, reverse video, sound and flashing lights.

Text should be legible

Icons should be easy to distinguish and read

Design Implication

Icons should enable users to readily distinguish

Bordering and spacing are effective visual ways of grouping information

Sounds should be audible and distinguishable

Speech output should enable users to distinguish between set of spoken words.

Text should be legible and distinguishable from background

Tactile feedback should allow users to recognise and distinguish different meaning

Involves first encoding and then retrieving knowledge

Involve filtering and processing what is attended to

Context is important in affecting our memory

Context

Context affects the extent to which information can be subsequently

Can be difficult for people to recall information that was encoded in different context

Attention

Make Information salient when it needs attending to

Use techniques that make things stand out like color, ordering, spacing, underling, sequencing and animation

Avoid cluttering the interface with too much information

Avoid using too much because the software allows it

Processing in memory

  1. Encoding is first stage of memory
  1. The more attention paid to something, the more it's processed in terms of thinking about it and comparing with other knowledge
  1. The more likely it is to be rememberd
  1. Users develop an understanding of a system through learning about and using it
  1. Knowledge is sometimes described as a mental model
  1. People make inferences using mental models of how to carry out tasks.

Craik described as internal constructions of some aspect of the external world enabling predictions to be made.

Involves unconscious and conscious processes (images and analogies)

Deep versus shallow models

  1. Encoding
  1. Comparison
  1. Response selection
  1. Response execution

Cognitive frameworks

Involves several processes including attention, memory, perception and learning

Internal

External

Mental models

Information processing

Gulf of execution and evaluation

Distributed cognition

External cognition

Embodied interaction

Human Information Processing

Types of processors

Perceptual

Cognitve

Motor processors

Types of Memory

  1. working memory
  1. Long-term memory