Yesterday's post was perhaps more cathartic than informational, but it should set the stage for more thought and discussion.  Today, let's put some more pieces in place.

Models are used everywhere.  Indeed, since the human brain consists of a very large but still finite number of neurons, it can be said that the human brain of necessity will construct models of reality from all the nearly infinite sources of input.  My concern with models isn't that they are bad, but rather, most people blindly accept them without questioning the validity of the model itself, the completeness and validity of the input, and the accuracy of the output.

I want to cover three heuristics (guiding rule or principle) that seem useful is constructing and analyzing models.  First, plain old common sense.  As said before, the human brain has constructed many models since birth and most likely, those models will prove useful as the person strives to continue existing.  Common sense is a vastly underused tool that can be used to understanding new models and problems.

Second, simplicity.  Occam's razor is a valuable principle that states that from competing models, the model with the fewest assumptions should be selected.  Simplicity allows the user to more accurately define the cost function in the model.  The more complex the model, by definition, the most time and energy that will be needed to work out all of the decision paths.

Finally, cui bono ('To who benefit?').  In nearly every decision, there are a multiple of actors with their vested interests and biases.  When analyzing a situation, an understanding of who benefits from the decision will quickly help understand the underlying model and bring clarity to the decision.