Bailey's Human Performance Model

What is Bailey's Human Performance Model?

Bailey's Human Performance Model (HPM) is a framework developed by Robert W. Bailey that describes how humans interact with systems across three levels of cognitive processing: skill-based, rule-based, and knowledge-based behaviors. This model helps designers understand the different mental processes users employ when interacting with interfaces and how to design for each level appropriately.

At the skill-based level, users perform automatic, unconscious actions developed through practice (like typing or scrolling). Rule-based behaviors involve following learned procedures or instructions when encountering familiar situations (like filling out a form). Knowledge-based behaviors require conscious problem-solving and decision-making in unfamiliar situations (like troubleshooting an error). The model emphasizes that users shift between these levels depending on their expertise and the complexity of the task.

Why is Bailey's Human Performance Model Important?

Bailey's Human Performance Model is important because it provides a framework for understanding how users process information and interact with systems at different cognitive levels. This understanding helps designers create interfaces that support users across varying levels of expertise and task complexity. By recognizing the different mental processes involved in user interactions, designers can create more intuitive and efficient interfaces.

The model is particularly valuable for designing complex systems where users may need to shift between automatic behaviors and conscious problem-solving. It helps identify potential sources of user error and cognitive load, allowing designers to create interfaces that minimize mistakes and mental effort. The HPM also provides insights for creating effective training materials and documentation that support users as they develop from novices to experts.

How to Apply Bailey's Human Performance Model?

To apply Bailey's Human Performance Model, design interfaces that support skill-based behaviors through consistent patterns and layouts that become automatic with use, facilitate rule-based behaviors with clear instructions, visual cues, and feedback that guide users through procedures, and enable knowledge-based behaviors by providing contextual help, explanatory information, and problem-solving tools when users face unfamiliar situations.

Consider the expertise level of your users and design accordingly—novices will rely more on knowledge-based processing and need more guidance, while experts will operate more at the skill-based level and benefit from shortcuts and efficiency features. Create interfaces that allow for smooth transitions between these cognitive levels as users gain experience. Test your designs with users of varying expertise levels to ensure the interface supports all three types of cognitive processing effectively.