Research can be engineered to give desired results. What is a strategy of "loading the dice" that some unethical researchers use?

Loading the dice means to put someone or something in advantage over the others, the metaphor comes from the idea of putting extra weight in one certain part of a dice and throw it, the results will tend to render the same number at each throw.

In research, one can tamper with the results to show the results they want with the safety of saying that research was conducted to come to this result.