Mental models are how the mind represents real, remembered, hypothetical, or imaginary situations. Models are like…
- …mental sketches. A simple sketch doesn’t retain all the details of what it represents — consider what’s left out in a stick figure sketch of a person. Sketches are iconic, i.e., they they preserve the overall structure of what they represent. Similarly, sketches are homomorphic representations, i.e., they include only pertinent details (stick figures routinely fail to represent a person’s fingers and internal organs). Models are both iconic and homomorphic.
- …an architect’s blueprints. A blueprint is a concise representation of a possibility — a building that could potentially occur in the real world. Blueprints are coherent, i.e., it’s impossible to create a blueprint of a building in which a basement is above the roof. Similarly, models represent coherent possibilities.
- …diagrams. Diagrams are powerful because you can learn new things by scanning them. Hence, new insights emerge from diagrams. Likewise, diagrams can represent abstract ideas, e.g., you can use a symbol in a diagram to represent abstract ideas — such as a star in a map to represent the capital of a city. Diagrams can even represent negation using, e.g., this symbol: ?. So, models can be scanned to yield emergent inferences; and they can represent abstract concepts.
- …comic strips. Comic strips don’t represent actions and events directly; instead, they represent discrete, critical points of a sequence of events in chronological order. Similarly, models are discrete and finite: they don’t represent infinite sequences, because cognitive resources are finite.