Universal Principles of Design, Updated and Expanded Third Edition

116 Mental Model

A mental simulation of how things work.

Mental models are internal representations of systems and environments derived from experience. People understand and interact with systems and environments by comparing the outcomes of their mental models with the real-world systems and environments. When the outcomes correspond, a mental model is accurate and complete. When the outcomes do not correspond, the mental model is inaccurate or incomplete. With regards to design, there are two basic types of mental models: mental models of how systems work (system models) and mental models of how people interact with systems (interaction models).¹

Engineers necessarily have strong system models—i.e., they know much about how a system works ...