Widely chosen for qualitative studies, this method brings the researcher into the paradigm while at the same time requires stringently unbiased reporting. The need for neutrality is what makes participant observation an especially demanding approach. Careful guidelines dictate how researchers assimilate into the groups, interact with their members, as well as collect and analyze the data. It is not unusual for this method to take several months or even years to accomplish, as Professor William M.K. Trochim points out in "Research Methods Knowledge Base."
Contrary to the researcher's intentional presence with participant observation, direct observation calls for keeping an inconspicuous profile. The point is to remove any potential bias by remaining detached from the respondents. Since there is no intended interaction with this method, it can be accomplished much faster and more easily by using one-way mirrors, pre-taped sessions or observation from afar, like watching a group of teenagers at the mall food court.
Researcher and respondent(s) directly interact in this method that uses informal guidelines about where the conversation will lead. This is especially valuable in a study with potentially broad implications; the further adrift respondents go in a stream of consciousness, the better the outcome from a findings perspective. At the same time, however, Trochim indicates the drawback to such structural free reign is a lack of simplicity during analysis and synthesis.
This method provides immediate and detailed information about a person or situation. A primary benefit is comparing study outcomes that use different qualitative methodologies to determine similarities and differences in the findings. Case studies are not guided by any one type of methodology, according to Trochim, which allows subsequent researchers to benefit from someone else's previous work as a baseline for examination.