BB cream is promoted as an all-in-one facial cosmetic product to replace serum, moisturizer, primer, foundation and sunblock. It can be worn alone as a tinted moisturizer, over serum and moisturizer as a regular foundation, and under powder, depending on the desired amount of coverage. 1  1 History.  2 Formulations.
Definition. Naturalistic observation is research that involves studying the subject of interest in its own environment, as it would occur in day-to-day life. The subject of interest may be human or non-human or it can be the behavior of living things or the interactions of non-living things with their environment.
There is often little attempt at analysis, quantitative or qualitative, but the observational study does uncover unknown phenomena and behaviors. Obtrusive naturalistic observational study is often used in anthropology, where a researcher lives with a remote tribe for a period of time and records their behavior.