Post on 05-Jan-2016
Human-Computer Interaction- user’s knowledge structure -
Prof. dr. Matthias RauterbergFaculty of Technology Management
Technical University Eindhoven
The Netherlands
© M. Rauterberg, TU/e 2
The fundamental design problem
implementedfunctions
perceivable userinterfaceforms
intendedsemantic
perceivedsemantic
designer’s mental model user’s mental model
© M. Rauterberg, TU/e 3
What is Human-Computer Interaction about?
systemuser
Working domain
Working system
Goal:Actual Performance=> Desired Performance
© M. Rauterberg, TU/e 4
Three different function types
Primary functions[application manager]
Secondary functions[dialog manager] Tertiary
functions[dialog manager]
Application object(s)
© M. Rauterberg, TU/e 5
The User Interface (1)
user
input/output interface
dialog moduledialogstate
applicationstate
perceptionaction
transformation
user interface
applicationobjects
application module
dialogobjects
applicationfunctions
dialogfunctions
presentation
© M. Rauterberg, TU/e 6
The User Interface
(2)
input-handler output-handler
Long-term memory
actionmodule
output-handler
inputoperation
visual"memory"
visual output
presentation
dialog module
dialogstate
applicationstate
transformation
user interface
applicationobjects (AO)
application module
dialogobjects (DO)
applicationfuncrtions
dialogfunctions
auditory"memory"
auditory output
tactile"memory"
tactile output
perception modulemotormemory
goal problemsolving module
Short-term memory
learningmodule
userexpectationplan
system[further reading]
© M. Rauterberg, TU/e 7
Several Notions of ‘Models’[Horst Oberquelle, 1984]
(1) a model of an axiom system(2) a known system with structure and behavior
analogous to the system under consideration(3) a prototypical system in the sense of 'model
farm'(4) an abstract description of the relevant
aspects of a system
© M. Rauterberg, TU/e 8
User’s Mental Models[Stephan Dutke: Mental Models-constructs of knowledge and understanding, 1994]
mental structure perception
cognition
action
external stimuli
Model:
e.g. visual system
e.g. Action Cycle
e.g. Fitts Law
Interface elements
© M. Rauterberg, TU/e 9
The Difference between Internal and External Memory
internal memory 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
Property Knowledge in the World Knowledge in the Head
Retrievability: Retrievability whenevervisible or audible or tangible.
Not readily retrievable.Requires memory search orreminding.
Learning: Learning not required.Interpretation substitutes forlearning.
Requires learning, which canbe considerable.
Efficiency of use: Tends to be slowed up by theneed to find and interpret theexternal information.
Can be very efficient.
Ease of use atfirst encounter:
High. Low.
Aesthetics: Can be unaesthetic andinelegant, especially if thereis a need to maintain a lot ofinformation.
Nothing need be perceivable,which gives more freedom tothe designer and can lead tobetter aesthetics.
© 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
© M. Rauterberg, TU/e 13
Activity Theory: the Complete Action Cycle
physical operation
feedback control of action
goal-, subgoal-setting
mental operation
task(s)
planning of execution selection of means
© M. Rauterberg, TU/e 14
User’s model: activity cycletask
description
feedback
cognitive process
observable action
goalinstanciation
Goa
l
instan
ciation
level
Actio
n le
vel
Cog
nitive
leve
lF
eed
ba
ckle
vel
[further reading]
© M. Rauterberg, TU/e 15
User’s mental structure
Goal
instanciation
level
Action level
M_3 h F_3 1 i hG_2F_10
Main menuMain menu
F-fileStart menuMsDOS
System
levelC
ognitive levelF
eedbacklevel
Regulation-driven goal setting
[further reading]
© M. Rauterberg, TU/e 16
How to investigate the user’s mental model?
Validation of the functional equivalence, computed by the similarity ratio (SR)
Adding goal setting structure
Reconstructed mental task modelHuman mental model
?
Observation of human behaviour
Folding
Adding sequential and temporal information Model
execution
original behavioural sequence simulated behavioural sequence
Device model
2
G_2
Start menu
M_3
Main menu
F_3
User key press
Automatic transition
Automatic transition
MsDOS
G_2
Main menu
F_3
Start menu
M_3
Automatic transition
Automatic transition
User key press
MsDOS
Main menu Main menu
F-fileStart menu
F_10 M_3 h F_3 1 i hG_2
MsDOS
Main menu Main menu F-file
Start menu
F_10 M_3 h F_3 1 i hG_2
MsDOS
1
3
4
5
6
i
© M. Rauterberg, TU/e 17
User’s learning process
complex system
operator
beginner
advanced
expert
learning time
interaction
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
s0
d h
s1
b
s2 s3F3
F9
CR
_
TAB
F2
"wall" of knowledge about unsuccessful behavior
"dales" of knowledge about successful behavior
© 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 atmy homepage