When choosing among alternatives, there is a guiding principle known as Occam's razor that loosely states the following:
If we have two or more equivalent explanations for the same phenomenon, we should choose the simpler one.
There are many justifications for this heuristic; one of them is related to the falsifiability criterion introduced by Popper. Another takes a pragmatic perspective and states that: Given simpler models are easier to understand than more complex models, we should keep the simpler one. Another justification is based on Bayesian statistics, as we will see when we discus Bayes factors. Without getting into the details of these justifications, we are going to accept this criterion as a useful rule of thumb for the moment, just something that sounds reasonable.
Another factor we generally should take into...
