Naturalistic vs. Artificial Observation: Naturalistic observation: Observers witness and record events that occur in the normal course of lives of the participants. Naturalistic observation has the advantage of being able to secure information in realistic context, but at the cost of not being able to control events witnessed. Artificial observation: Occurs in artificial settings or situations. Artificial observation has the advantage of controlling conditions and eliciting relevant behavior, but at the cost of sacrificing realism.
Each design has strengths and weakness. Which design a researcher uses depends on the research question and the goal of research. Decisions about data source and research design depend on the purpose of study. There is no perfect data source or research design. Some data sources and some methods are better suited for some purposes than for others.