definition of a naturalist
He just might grow up to be a naturalist, or a scientist who specializes in studying nature. A biologist whose interest lies primarily in the study of plants or animals can be called a naturalist, although these days it's more likely she'll be called a natural historian, a botanist, or a zoologist.
naturalistic observation An observation of behavior in a more or less natural setting without any attempt by the observer to intervene. (87) observer bias Systematic errors in observation resulting from the observer's expectancies regarding the outcome of a study (i.e., expectancy effects).