Understanding humans

1
Understanding humans

• Understanding human physiology and implications
  on design

2
Agenda

• Questions
• HW1 IRB and HW2
• Project talk
• Humans as information processors
• DFAB sensory discussion

3
Project talk

• All teams set (perhaps)
• Topics
• Mentors

4
Preparing for Part 1
5
Basic human capabilities

• Humans evolve much more slowly than technology
• There are limits to human capabilities

6
Processing models

• DFAB
• sense/input descriptions
• storage/memory models
• Card, Moran Newell paper (later)
• Model Human Processor
• perceptual / motor / cognitive

7
Humans as I/O machines

• Senses
• vision
• hearing
• touch
• smell/taste
• Feed sensory memory, then processing
• What are the design implications?

8
Design implications

• Vision
• e.g., acuity and color, optical illusions
• Hearing
• frequency response, filtering
• Touch/motor movement
• Fitts law
• Tactile sensitivity

9
Memory

• 3 kinds
• distinguished by
• main code type
• storage capacity
• decay time of an item
• relationship

10
Sensory / Perceptual Memory

• physically encoded
• impacted by physical characteristics of signal
• low capacity
• rapid decay (msec)

11
Short-Term or Working Memory

• symbolic, nonphysical acoustic or visual coding
• 7 plus/minus 2 chunks
• decay 5-226 sec

12
What is a chunk

• a meaningful grouping of information
• 4 7 9 3 6 1 9 0 4 9
• vs
• 404 894 7243
• User and task dependent

13
Long term memory

• semantic information
• capacity (limitless?)
• no decay?
• Catch Retrieval depends on associations

14
Principles for retrieval

• How information is perceived, understood and
  encoded determines likelihood of retrieval

15
Other User Characteristics