1. Human-Computer Interaction - user’s knowledge structure -
Prof. dr. Matthias Rauterberg
Faculty of Technology Management
Technical University Eindhoven
The Netherlands

2. The fundamental design problem
designer’s mental model
user’s mental model
perceived
semantic
intended
semantic
perceivable user
interface
forms
implemented
functions
© M. Rauterberg, TU/e

3. What is Human-Computer Interaction about?
Working domain
Goal:
Actual Performance
=>
Desired Performance
Working system
user
system
© M. Rauterberg, TU/e

4. Three different function types
Secondary functions
[dialog manager]
Tertiary
functions
[dialog
manager]
Primary functions
[application manager]
Application object(s)
© M. Rauterberg, TU/e

5. The User Interface (1) user action perception input/output interface
presentation
dialog module
dialog
dialog
dialog
state
objects
functions
application
application module
state
application
application
transformation
functions
objects
user interface
© M. Rauterberg, TU/e

6. The User Interface (2) [further reading] input-handler output-handler
Long-term memory
action
module
input
operation
visual
"memory"
visual output
presentation
dialog module
dialog
state
application
transformation
user interface
objects (AO)
application module
objects (DO)
funcrtions
functions
auditory
auditory output
tactile
tactile output
perception module
motor
memory
goal
problem
solving module
Short-term memory
learning
user
expectation
plan
system
[further reading]
© M. Rauterberg, TU/e

7. Several Notions of ‘Models’ [Horst Oberquelle, 1984]
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8. User’s Mental Models [Stephan Dutke: Mental Models-constructs of knowledge and understanding, 1994]
external stimuli
Interface elements
perception
e.g. visual system
mental structure
cognition
e.g. Action Cycle
action
e.g. Fitts Law
© M. Rauterberg, TU/e

9. The Difference between Internal and External Memory
the mental model of the user about the external world is always incomplete
all necessary information which is not in the internal memory must be provided by the environment (the “external memory”)
© M. Rauterberg, TU/e

10. Knowledge in the World and in the Head
© M. Rauterberg, TU/e

11. User’s motor behavior: Fitts' Law
T = k log2(D/S + 0.5) with k ~ 100 msec
T = time to move the hand to a target D = distance between hand and target S = size of target
Fitts' Law is a model to account for the time it takes to point at something, based on the size and distance of the target object.
Fitts' Law and variations of it are used to model the time it takes to use a mouse and other input devices to click on objects on a screen.
Fitts' Law can be applied by designers to suggest moving target buttons closer and making them larger for extremely commonly used buttons. In detail, applying the formula can be extremely useful for exact design of time-critical applications.
© M. Rauterberg, TU/e

12. The Visual Perception System
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13. Activity Theory: the Complete Action Cycle
task(s)
goal-, subgoal-setting
feedback
planning of execution
control of
action
selection of means
mental operation
physical operation
© M. Rauterberg, TU/e

14. User’s model: activity cycle
task
description
cognitive process
Cognitive level
feedback
Feedback
level
goal
instanciation
Goal
instanciation
level
observable action
Action level
[further reading]
© M. Rauterberg, TU/e

15. User’s mental structure
Regulation-driven goal setting
Cognitive level
System level
instanciation
Goal
level
Feedback
level
[further reading]
Action level
F_10
G_2
M_3 h
F_3 1 i h
MsDOS
Start menu
Main menu
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Main menu
F-file

16. How to investigate the user’s mental model?
© M. Rauterberg, TU/e

17. User’s learning process
We (1996) found a negative correlation between Behavioral-Complexity and Mental-Complexity
[further reading]
© M. Rauterberg, TU/e

18. mental activity is like the ‘flow of a river’
© M. Rauterberg, TU/e

19. Learning means ‘digging’
learning process
[further reading]
© M. Rauterberg, TU/e

20. User’s Behavior: an example
"dales" of knowledge about
successful behavior s0 d h
"wall" of knowledge
about unsuccessful
behavior s1 CR b F9 F2 s2 F3 s3
TAB _
© M. Rauterberg, TU/e

21. User’s real knowledge structure
knowledge about
unsuccessful behavior
knowledge about
successful behavior
© M. Rauterberg, TU/e

22. Thank you for your attention
More at
my homepage
© M. Rauterberg, TU/e