Participant observation is based on living among the people under study for a lenghty period, usually a year, and gathering data through continuous involvement in their lives and activities. The ethnographer begins systematic observation and keeps daily field notes, in which the significant events of each day are recorded along with informants' interpretations. Initial observations focus on general, open ended data gathering derived from learning the most basic cultural rules and usually the local language as well. This initial orientation process is important not only for providing a background for more narrowly focused investigation but also helps the anthropologist to gain rapport with his/her informants, avoid breaches of etiquette, and test out whether the original research objectives are meaningful and practical in the local situation.
My first research project was located in Ghana, West Africa and focused on the social and economic organization of a market place system that connected a large commercial town to a rural hinterland. The main economic base of the locality was cocoa production for export, which was organized through a government marketing board and not the normal marketing system I was investigating. However, I was interested in all sorts of other activities in order to achieve a wide perspective on the local economy and culture. My fellow harvesters were all members of a reciprocal work party, who help on each others farms in turn during periods of peak labour demand. Although no payments are exchanged, everyone gets a reward of food and drink from the host farmer at the end of the day, and a party atmosphere dominates the day's events.
After the initial orientation or entry period, which may take 3 months or longer, the researcher follows a more systematic program of formal interviews involving questions related to research hypotheses and specialized topics. Several different methods of selecting informants are possible. Usually a few key informants (between 10-20) are selected for in-depth sessions, since the investigation of cultural patterns usually calls for lengthy and repeated open ended interviews. Selection of such a small number does not allow for strict assurance of a representative sample, so the anthropologist must be careful to choose subjects who are well informed and reliable. Ethnographic researchers will also train informants to systematically report cultural data and recognize significant cultural elements and interconnections as the interview sequences unfold.
Key informant selection is known as judgement sampling and is particularly important for the kind of qualitative research that characterizes ethnography. Anthropologists will very frequently also need to carry out quantitative research from which statistically validated inferences can be drawn. Accordingly they must construct a either larger random sample or a total population census for more narrowly focused interviewing according to a closed questionnaire design. Other important quantitative data might include direct measurement of such items as farm size, crop yield, daily caloric or protein intake, or even blood pressure or other medical data, depending on the anthropologist's research focus. Aside from written observation and records, researchers will often provide ethnographic representations in other forms, such as collected artifacts, photographs, tape recordings, films, and videos.
To illustrate the range of research techniques that anthropologists regularyly employ, I can enumerate 5 systematic data gathering procedures that I used to study a Ghanaian marketing system: