Fallacy definition (short name: insufficient_sample)
This is a conclusion based on insufficient or biased evidence. In other words, you are rushing to a conclusion before you have all the relevant facts.
This crow is black. Therefore all crows are black.
It has to be noted that Hume presented all inductive reasoning as falsy by this very fallacy. He stated that whatever the number of times an experiment is repeated, the next experiment’s result can not be predicted by the results of the previous ones. Although his argument is valid, insufficient sample fallacies must be examined very closely, because they are often the only way to build knowledge, and to produce inductive reasoning.