Sarah, a graduate student in psychology, just heard about a five-year-old child who has already learned calculus. she is thinking about doing an in-depth study of the child for her dissertation because such early-life math skill is so rare. sarah is considering which research method?

Sarah is considering "Case Study".

A case study is an inside and out investigation of a specific circumstance as opposed to a broad measurable study. It is a strategy which is used to limit an extremely expansive field of examination into one effectively researchable subject. The A case study has been particularly utilized in sociology, psychology, human sciences and nature.