Methodology I: Task Analysis - Foundations for Designing User-Centered Systems - page 316

Table 11.5 Example GOMS model, written using NGOMSL notation, for telephone
dialing taken from St. Amant et al. ( 2005 )
Task item: T1 [[ tasks will go from T1 to T11 to dial [phone] ]]
Name is T1.
Digit is "8".
Next is T2.
Visual object: first digit
Content is "8".
Task item: T2
Name is T2.
Digit is "1".
Next is T3.
Visual object: second digit
Content is "8".
. . .
Task item: T11
Name is T11.
Digit is "8".
Next is NONE.
Visual object: second digit
Content is "1".
Method for goal: Dial Number
Step. Store T1 under <current task name>.
Step Check for done.
Decide: If <current task name> is T11, Then
Delete <current task>;
Delete <current task name>;
Return with goal accomplished.
Step. Get task item whose Name is <current task name>
and store under <current task>.
Step. Accomplish goal: Dial Digit.
Step. Store Next of <current task> under <current task name>.
Goto Check for done.
Method for goal: Dial Digit
Step. Look for object whose Content is Digit of <current task>
and store under <target>.
Step. Point to <target>; Delete <target>.
Step. Click mouse button.
Step. Verify "Correct digit pressed".
Step. Return with goal accomplished.
The KLM is usually applied where there is just one person interacting with a
computer-based system. It is a fast and approximate way to compute how long
users will take to perform a unit task. A unit task is essentially a small cognitively
manageable task. Large tasks can be decomposed into several unit tasks, although