What is anecdotal evidence? when should it be used (and not used) in a research paper?

Anecdotal evidence is evidence based from personal stories of the author or by someone that the author knows. They are not good for research papers because they are often highly personal and biased, as well as difficult to prove as they are often over-exaggerated and full of lies in order to make the stories more fun.

It shows that the milk is like life to the boy