Goals-what we need to do

Operator-steps to do it

Methods-steps of operations to satisfy our goals

Selections-which method to use

--GOMS Models -

-KLM simplified CMN- GOMS

-NGOMSL more rigorously defined version of KLM

-CPM-GOMS uses cognitive, perceptual and Motor operators in a critical path method(pert chart) to show how activities can be performed in parallel

-Benefits - functionality, execution time, learning time

-Limitations - assumption of error-free performance

--GOMS is a Tool for Comparing alternative Designs