What is GOMS Model?

GOMS, which stands for Goals, Operators, Methods, and Selection rules, is a cognitive modeling framework used to describe and predict human behavior in computer-based tasks. The framework was developed by Card, Moran, and Newell in the 1980s and is still widely used today in various fields such as human computer interaction, psychology, and computer science.

The basic idea behind GOMS is to break down a task into its component parts and model each part as a set of operations that a user can perform. The model then uses selection rules to determine which operation to perform next based on the user’s current goal and the available options.

Goals in GOMS refer to the overall objectives that a user is trying to achieve in a task. For example, in a word processing task, the goal might be to write a report. Operators are the basic building blocks of the model and represent the individual actions that a user can perform. In a word processing task, operators might include typing, selecting text, or formatting.

Methods are higher level sequences of operators that represent common patterns of behavior. For example, a method might be to copy and paste text from one part of a document to another. Selection rules determine which operator or method to perform next based on the user’s current goal and the available options.

One of the main advantages of GOMS is that it allows researchers to make predictions about how long a task will take and how many errors a user is likely to make. This is because the model can be used to simulate different scenarios and predict how users will perform under different conditions.

GOMS can also be used to design and evaluate user interfaces. By breaking down a task into its component parts and modeling user behavior, designers can identify potential usability issues and make improvements to the interface. For example, a GOMS model might reveal that a certain task requires too many steps or that certain options are too difficult to find.

Despite its many advantages, GOMS does have some limitations. One of the main criticisms of the framework is that it is often too simplistic and does not capture the full complexity of human behavior. Additionally, GOMS models can be time-consuming and difficult to create, requiring a high level of expertise in cognitive psychology and human-computer interaction.

Overall, GOMS is a powerful tool for modeling human behavior in computer based tasks. By breaking down a task into its component parts and modeling user behavior, researchers and designers can make predictions about how users will perform and identify potential usability issues. While GOMS has some limitations, it remains a valuable framework for understanding and designing user interfaces.

Vadzim Vrubleuski
UX/HCI Researcher | Tech Innovator | Research Psychologist https://vrubleuski.com

References
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