User Modeling

These are explicit respresentations of users that predict user behavior and product usability.

Keystroke Level Model

• Rules for applying the KLM
• Predicts task length for an expert user
• Review example in class

We will practice this method on this unit converter.

Cognitive models of user interaction

• Running simulations of users interacting with a product
• Article on simulating web navigation
• Jar file for Web simulation (after downloading jar file, type "java -classpath demo.jar SimDemo" at command prompt)
• Latent semantic analysis --- tools for comparing the semantic relatedness of labels

GOMS (Goals, Operators, Methods, Selection) hierarchical analysis

The four components of a GOMS analysis

• Goal -- desired result; does not specify means for achieving result
• Operator -- a primitive step for achieving a goal; often a user action
• Method -- a plan for achieving a goal consisting of operators
• Selection -- a rule for recommending a method that achieves a goal

Properties

• Explicitly represent the user's knowledge and actions in the form of goals and subgoals
• The depth of the hierarchy indicates the complexity of the product and task
• Usage statistics of task components can be applied to other tasks that use the same components
• Article reviewing GOMS approaches

We will review a GOMS example in class.

Issues for discussion

• Advantages of user modeling
• Costs of user modeling