I understand that the assumption made in a fixed effects model is that there is a basic understanding of the included parameters, e.g. there is a proven theory or previous experiments have shown non-random effects of the parameters.
In a random effects model, however, a parameter is treated as a random variable. Effects are completely random samples form a larger population.
This leads to my question: Why, then, is the random effects model--at least according to Wikipedia (https://en.wikipedia.org/wiki/Random_effects_model) --considered a special case of the fixed effects model?
The random effects model is a special case of the fixed effects model.
To me, it more seems as if they are complete opposites.