HUMAN COMPUTER INTERACTION - Model Human Processor

1. Model Human Processor

2. A model of human information
processing
Model Human Processor
•Detailed model of how computer users process
information
•Intended to help designers do predictions
•Consists of specialised concurrent processing
units and memories
•characterised by speed, decay time, capacity,
encoding

3. Working memory
Long-term memory
Auditory
memory
Visual
memory
Stimulus
Perception
Cognitive
processor
Motor
processor
Model Human Processor

4. Principles of the MHP
• Perception takes time - depends on stimulus
intensity
• Processing takes time - depends on task
demands, information load, practice
• Different encoding used at different stages
• Users act rationally (most of the time):
Goals + Task + Operators + Inputs
+ Knowledge + Processor limits
Behaviour

5. Applications in HCI
• The GOMS and KLM analysis techniques
• Identifies kinds of processing and memory
• Identifies possible concurrency

6. Comparing the models
• MHP almost exclusively about what goes on
inside the head
– Focus on human performance - especially time
• Norman's model more about human-machine
interaction
– without saying how processes are implemented
or what exists in the head
– Distinguish between "in the head" and "in the
world"

7. Knowledge in the head and in
the world
• Knowledge needed to translate intentions
into plans and actions may be
– remembered by the user (in the head)
• e.g. unix commands
– embedded in the devices used (in the world)
• e.g. direct manipulation interfaces