IFI7159 M2

1. [M2]
classical theories
cognitive modeling

2. roles of theory

3. theory as paradigm
that which underpins
research design

4. theory as a lens
that which may inform our
understanding of the
phenomenon under
investigation

5. theory as new knowledge
that which may emerge
from our study

6. roles of theory in HCI

7. descriptive
explanatory
predictive
prescriptive
generative

8. what other
conceptualisations did you
find when going over your
assignments?

9. classical theories

10. (raw) cognitive psychology
(applied) basic research
cognitive modeling

11. but let’s focus on cognitive
modeling

12. direct manipulation

14. direct manipulation relates to
distance and engagement

15. distance between one’s
thoughts and the
requirements of the system
under use

16. engagement as in the feeling
that one is directly
manipulating the objects of
interest

17. theory of action

19. gulf of
execution

20. gulf of
evaluation

21. the gulf of execution
represents the difficulty the
user has in translating a
psychological goal into a
physical action

22. for example, the goal learn more about
avocados is purely psychological
the user of a hypertext system on the WWW will
need to see the available links, recognize the
appropriate choice, and use the mouse to point
and click on that link
thus, in order to learn more about avocados, the
user needs to execute a set of physical steps

23. the gulf of evaluation
represents the user's
difficulty in evaluating
whether the response of the
computer system meets the
desired goal

24. in the previous example, the user would need to
perceive the system response, examine the
resulting node, and assess whether it presented
the proper information about avocados

25. Keystroke-Level Model

26. KLM quantifies operations
such as…
K Press a key or button
P Point to a target on the
display
H Home hands on input device
D Draw a line segment
M Mentally prepare for an action
R (system response time)

28. Goals, Operators,
Methods, Selectors

29. goals are what the user wants to achieve and
can be broken down into subgoals
operators are actions performed in service of a
goal and can be perceptual,
cognitive or motor acts
methods are sequences of operators and
subgoal invocations accomplishing
a specific goal
selection rules represent the user’s knowledge
of which method should be applied

30. GOMS is good at
modeling goal-directed
tasks

31. GOMS is good for…
comparing different designs
building a help system
parametric analysis
profiling

32. GOAL: DELETE-FILE
. GOAL: SELECT-FILE
. . [select: GOAL: KEYBOARD-TAB-METHOD
. . GOAL: MOUSE-METHOD]
. . VERIFY-SELECTION
. GOAL: ISSUE-DELETE-COMMAND
. . [select*: GOAL: KEYBOARD-DELETE-METHOD
. . . PRESS-DELETE
. . . GOAL: CONFIRM-DELETE
. . GOAL: DROP-DOWN-MENU-METHOD
. . . MOVE-MOUSE-OVER-FILE-ICON
. . . CLICK-RIGHT-MOUSE-BUTTON
. . . LOCATE-DELETE-COMMAND
. . . MOVE-MOUSE-TO-DELETE-COMMAND
. . . CLICK-LEFT-MOUSE-BUTTON
. . . GOAL: CONFIRM-DELETE
. . GOAL: DRAG-AND-DROP-METHOD
. . . MOVE-MOUSE-OVER-FILE-ICON
. . . PRESS-LEFT-MOUSE-BUTTON
. . . LOCATE-RECYCLING-BIN
. . . MOVE-MOUSE-TO-RECYCLING-BIN
. . . RELEASE-LEFT-MOUSE-BUTTON]
*Selection rule for GOAL: ISSUE-DELETE-COMMAND
If hands are on keyboard, use KEYBOARD-DELETE-METHOD,
else if Recycle bin is visible, use DRAG-AND-DROP-METHOD,
else use DROP-DOWN-MENU-METHOD