Faulkner X., 2000, Usability engineering

[Admin]

27. Faulkner X., 2000, Usability engineering,New York, McMillan Press.
a. Usability approaches :
i. On education
ii. Incorporating human factors into the process design
b. Criteria of usability :
i. Effective
ii. Efficient
iii. Satisfying
c. Effectiveness: Whether atask could be accomplished with the specified system and within a given time frame.
d. Learnability: How easy a system is to learn can be measured in term of novice users experience of learning how to operate it.
e. Error and error rate: If the users can carry out tasr#k without making errors ten the system will be faster and more efficient to use since it requires less efforts.
f. Time : How much time a task takes to complete and how much time is spent on error is also used to jugde the efficiency of system.
g. Approaches in evaluating system:
i. Analytical evaluation: About how complex the system and how long a task might be performed.
ii. Empirical method: consists of an analysis of user performance in relation to the proposed system.
h. Cooperative evaluation is impressive fro its simplicity:
i. Recruiting users who will help in the evaluation
ii. Preparing tasks
iii. Interacting with the user and the system and recording what happens
iv. Summarizing the observation
i. Field Studiy is conducted in the user’s environment. It will be full of the distractions and extraneous noise that a real working situation necessarily contains- this can make observation difficult. However it allows usability engineer to view the system as part of the end-user’s total environment.
j. Nielsen Heuristics :
i. Simple and natural dialogue
ii. Speak the user’s language
iii. Minimise the user’ memory load
iv. Consistency
v. Feedback
vi. Clearly marked exits
vii. Shortcuts
viii. Good error message
ix. Prevent errors
x. Help And documentations
k. Shneiderman’s heuristics
i. Strive for consistency
ii. Enable Frequent users to use shortcut
iii. Offer informative feedback
iv. Design dialogs to yield closure
v. Offer simple error handling
vi. Permit easy reversal of actions
vii. Support internal locus of control
viii. Reduce short term memory load.
l. Norman
i. Use both knowledge in the world and knowledge in the head.
ii. Simplify the structure of the task
iii. Make things visible, breigde the gulfs of execution and evaluation
iv. Get the mapping right
v. Exploit the power of constraints both natural and artificial.
vi. Design for error
vii. When all else fails, standardise.