Cherry-picking is when you select evidence based on whether it supports the conclusion you want to draw, rather than on reliability of the evidence.
Examples could be ignoring sources or data that do not support your conclusion.
If cherry-picking is detected, teachers will often be in doubt whether or not it is intentional. Unintentional cherry-picking will often result in a lower grade. Intentional cherry-picking may in severe cases be considered as a kind of falsification and sanctioned accordingly. .