Fallacies of Explanation
An explanation is a form of reasoning which attempts to answer the question "why?" For example, it is with an explanation that we answer questions such as, "Why is the sky blue?" Explanation can be based on a scientific theory, on agency, or purpose (teleology). In this case, the explanation of why the sky is blue might begin in terms of the composition of the sky and theories of reflection. Of course, blue, as we commonly refer to it, does not refer to a wavelength of light but to that color we see in our mind's eye (qualia) when we look at the sky, a blueberry, or iodine. And the phenomenelogical answer to why the sky appears blue to our minds will be of a different sort. If one is open to the idea that the universe was created or designed for a purpose or with intentionality, one might also venture an answer in terms of teological or aesthetics.
An explanation is intended to explain why some phenomenon happens. In this case, there is evidence that the phenomenon occurred, but it is trumped up, biased or ad hoc evidence.
An explanation is intended to explain who some phenomenon happens. The explanation is fallacious if the phenomenon does not actually happen or if there is no evidence that it does happen.
The theory advanced to explain why some phenomen occurs cannot be tested. We test a theory by means of its predictions. For example, a theory may predict that light bends under certain conditions, or that a liquid will change colour if sprayed with acid, or that a psychotic person will respond badly to particular stimuli. If the predicted event fails to occur, then this is evidence against the theory. A thoery cannot be tested when it makes no predictions. It is also untestable when it predicts events which would occur whether or not the theory were true.
The theory doesn't explain anything other than the phenomenon it explains.
Theories explain phenomena by appealing to some underlying cause or phenomena. Theories which do not appeal to an underlying cause, and instead simply appeal to membership in a category, commit the fallacy of limited depth.