Melinda is at a museum, watching how parents interact with their children. She counts the number of times scientific explanations are given to girls versus boys. This is an example of

Naturalistic observation

Explanation:

Natural observation is a very common and useful research method in which a researcher can observe a subject in the natural environment.Natural observation is valuable when a researcher wants to get more information about people in a particular social or cultural context, but natural information cannot be gathered in any other way.Observed behaviors occur in natural settings, natural observations have strong structures and facial authenticity