1. Can you see two user interfaces below? Interface-1 has list-boxes while interface-2 has radio-buttons.
2. You are supposed to record your reponses using interface-1 and then interface-2.
3. Before you start recording your responses on interface 1 press Start button to start recording time.
4. Then record your responses for each subject using interface 1 (list-boxes).
5. After you finish giving responses for all subjects press Stop button to stop recording of time.
6. Repeat the same procedure from 3 to 5 for interface 2 ( radio-buttons ) .
7. Reset the timer if you wish to repeat the experimentation again.
8. After performing the experiment read the discussion at the end.After performing the experiment read the discussion at the end.
Why is there a difference in the task completion time? Is it because of difference in interaction elements chosen and their layout? Is there a cognitive perceptual factor contributing to task completion time? An interaction task is always guided by the user goals, interface operators and alternative methods available on interface for acheiving those goals. In this respect the above two interfaces can be analysed using GOMS model. Task analysis using KLM-GOMS model for above interfaces can predict the task completion time before hand. Thus the time and cost for user-testing is reduced. You are therefore adviced to build a GOMS model for the above task for both interfaces and compare the predictated time with the actual time taken for the task.