For example, a student once came into my office with an idea that he had been working on since he was very young about how electricity might be described and modeled. It was apparent that, although his idea was clever and inventive, it did not coincide with some of the things we know about the electromagnetic force. Rather than squelch this student's idea outright I simply informed him that since he was a freshman physics major he would learn a lot about electricity during the next four years of college. I suggested that he compare what we know about how the electromagnetic force works with his model and see if his model was able to accurately describe what we know from experimental observation. If it didn't, he'd have to revise or reject his model. If it did, his model may be correct.
In any effort to determine if an idea is true or not, it is vital to compare the predictions of the idea with what is already known to be true. If an idea contradicts known truth, then the idea cannot itself be true.