CMN-GOMS stands for Card, Moran and Newell GOMS. CMN-GOMS is the original version of the GOMS

GOMS

GOMS is a kind of specialized human information processor model for human computer interaction observation. Developed in 1983 by Stuart Card, Thomas P. Moran and Allen Newell, it was explained in their book The Psychology of Human Computer Interaction...

 technique in human computer interaction. It takes the name after its creators Stuart Card

Stuart Card

Stuart K. Card is an American researcher and Senior Research Fellow at Xerox PARC. He is considered to be one of the pioneers of applying human factors in human–computer interaction.- Biography :...

, Thomas P. Moran

Thomas Moran

Thomas Moran from Bolton, England was an American painter and printmaker of the Hudson River School in New York whose work often featured the Rocky Mountains. Moran and his family took residence in New York where he obtained work as an artist...

 and Allen Newell

Allen Newell

Allen Newell was a researcher in computer science and cognitive psychology at the RAND corporation and at Carnegie Mellon University’s School of Computer Science, Tepper School of Business, and Department of Psychology...

 who first described GOMS in their 1983 book The Psychology of Human Computer Interaction.

Overview

This technique requires a strict goal-method-operation-selection rules structure. The structure is rigid enough that the evaluator represents the tasks in a pseudo-code format (no formal syntax is dictated). It also provides a guide for how to formulate selection rules. This method can also be used to estimate the load the task places on the user. For instance, examining the number of levels down the task-tree that a goal branch is can be used to estimate the memory demand the task places on the system. The process must remember information about all of the levels above the current branch.

This technique is more flexible than the Keystroke-Level Model

KLM (human computer interaction)

Keystroke-level model, sometimes referred to as KLM or KLM-GOMS, is an approach to human–computer interaction , based on CMN-GOMS, developed by Card, Moran, and Newell, and explained in their book The Psychology of Human-Computer Interaction, 1983...

 (KLM) because the pseudo-code is in a general form. That is, it can be executed for different scenarios by going down different branches, while KLM’s procedure is a simple list that has to be recreated for each different task.

Example of a simple goal

Deleting a file in Windows Explorer

Windows Explorer

This article is about the Windows file system browser. For the similarly named web browser, see Internet ExplorerWindows Explorer is a file manager application that is included with releases of the Microsoft Windows operating system from Windows 95 onwards. It provides a graphical user interface...

 (NOTE: not all goals are fully expanded in this example).

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

Notations

• This article incorporates text from Dr. G. Abowd: GOMS Analysis Techniques - Final Essay, which has been released into GFDL by its author (see http://en.wikipedia.org/w/index.php?title=Talk:GOMS&oldid=19999716).