I need a more specific word than illogical.
Say an educational psychologist collected some data about someone by having two people fill out a questionnaire that is a well known, reputable, published, normed instrument. The two questionnaires yielded totally different results, and then the psychologist "resolved" the "discrepancy" by conveniently throwing out the questionnaire that didn't support the conclusion he wanted to draw.
I think we don't say his conclusion is fallacious. I think we can say it is illogical. Is there a more specific, apt word for this situation? A single word if possible.