Better models, better decisions

What is a mental model?

A mental model is a simplified explanation of how something works. Nobody carries the whole world in their head, so we reason with models instead: supply and demand, compound interest, the idea that a chain is only as strong as its weakest link. The psychologist Kenneth Craik suggested in 1943 that the mind builds small-scale models of reality to predict what will happen next.

A good model lets you see a situation quickly and ask the right question. A missing model leaves a blind spot: you can only see the problems you have a way of thinking about. That is why the useful thing is not one model but many, from different fields, that check and strengthen each other. Charlie Munger called this a latticework of mental models, and it gives this site its name.

Why architects need them

Architecture is mostly decisions made under uncertainty, with incomplete information, about systems and organisations too large for anyone to hold in their head. Where to draw a boundary, what to build or buy, how a system will fail, why a team keeps missing its targets, how to get a decision agreed: each has a model that makes it easier to think about, and most have been named by someone who learned the hard way.

Latticework collects 129 of those models across 11 disciplines for Solution, Domain and Enterprise Architects. Each is rewritten for the decisions architects actually face, with an explanation of why it works, where it applies, how to use it, an example, the questions to ask, when not to use it and how it can mislead you. Every model has a diagram that explains the idea at a glance, links to at least one reference, and shows when it was last reviewed.

How to use this site

• Start from a problem Pick what you are seeing and get the models that explain it.
• Follow a playbook Work through a short sequence of models for a common moment, as a worksheet if you like.
• Browse the library Filter by discipline, role or situation, or search by name, thinker or symptom.
• See the lattice Explore how the models connect, and compare those that pull in opposite directions.
• Bring it to your team Use ready-made formats, from ten minutes in a stand-up to a session on a real decision.

There are 45 symptoms, 28 playbooks and 56 thinkers to start from.

Sources and credit

The ideas belong to the people who named them, and every model page credits its originators and links to at least one reference, chosen from their own writing wherever possible. Short quotations are attributed to their authors. The explanations, examples and diagrams are written for this site; the example scenarios are illustrations, not accounts of real companies.

The approach was inspired by Farnam Street, whose writing on mental models introduced many people to Munger’s idea. Latticework is an independent project and is not affiliated with or endorsed by Farnam Street or any of the authors it cites.

The text and diagrams are licensed under CC BY-SA 4.0: you may share and adapt them, with credit, under the same licence. Quotations and the cited works belong to their authors. Spotted a mistake or a model we are missing? Tell us.

A word of caution

Models are maps, not the territory. Each page ends with how the model can mislead you, because the most dangerous model is the one applied everywhere. Use them to ask better questions, not to settle arguments.