- [[computation vs analytic tractability]], [[uses of models]] # Idea Models take the following forms/approaches. Embodiment models: They aim to be realistic and embody reality while stripping away the details. That is, [[models simplify the world]]. Analogy models: We abstract from reality and use analogies to understand complex phenomena. We think of crime spreading like diseases. While the embodiment approach stresses **realism**, the analogy approach tries to capture the **essence** of a process, system, or phenomenon. Alternative reality models: They don't try to represent or capture reality. These are [[thought experiments]]. [[Page 2018 model thinker - what you need to know to make data work for you]] > Whether embodying a more complex reality, creating an analogy, or building a made-up world for exploring ideas, a model must be communicable and tractable. We should be able to write the model in a formal language such as mathematics or computer code. When describing a model, we cannot toss out terms like beliefs or preferences without providing a formal description. Beliefs can be represented as a probability distribution over a set of events or priors. Preferences can be represented in several ways such as a ranking over a set of alternatives or as a mathematical function. # References