An opinion formed before obtaining adequate evidence, especially as the result of bias or prejudice
Your preconceptions about something are beliefs formed about it before you have enough information or experience. Did you have any preconceptions about the sort of people who did computing?. a belief or opinion that you have already formed before you know the actual facts, and that may be wrong preconception about/of
an opinion formed beforehand without adequate evidence; "he did not even try to confirm his preconceptions"
an opinion formed beforehand without adequate evidence; "he did not even try to confirm his preconceptions
{i} presupposition, bias, prejudice; previously formed opinion, previously determined viewpoint