Identify the error in reasoning. 'Two graduates of that polytechnic were rude to me at the bank, so graduates of that polytechnic are rude people.'

A conclusion about an entire group is drawn from a sample of only two people, which is far too small to support it. That is a hasty generalisation. Begging the question assumes the conclusion in the premise, an appeal to pity uses sympathy in place of evidence, and a slippery slope predicts an unlikely chain of consequences.