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.

Examples

1. "The reason why most bachelors are timid is that their mothers were domineering." (The illogical reasoner attempts to explain why most bachelors are timid, but it can be shown that his generalization is based on two bachelors he once knew, both of whom were timid. This form of evidence is often called "anecdotal evidence".)
2. "The reason why I get four or better on my evaluations is that my students love me." (This is a fallacy if the evaluations which score four or less are discarded on the grounds that the students did not understand the question.)
3. "The reason why Alberta has the lowest tuition in Canada is that tuition hikes have lagged behind other provinces." (Lower tuitions in three other provinces - Quebec, Newfoundland and Nova Scotia - were dismissed as "special cases" [again this is an actual example])

Proof

Identify the term being defined. Identify the conditions in the definition. Find an item which is an instance of the term but does not meet the conditions.