Gathering Data About Culture

In most ethnographic fieldwork, only a portion of the host society is actually studied intensively. Due to the practical impossibility of observing and talking at length with everyone, only a sample of a community is selected. If the sample of people is chosen carefully, there is an expectation that it will be representative of the entire community. This is referred to as a probability sample --i.e., a sample that has a high probability of reflecting the entire population. Choosing who will be in the sample can be difficult, especially at the beginning of a research project when the first contacts are made and the composition of the society and its culture are still poorly understood.
Usually ethnographers opt for one of three types of probability samples--random, stratified, or judgment. A random sample is one in which people are selected on a totally random, unbiased basis. This can be accomplished by assigning a number to everyone in a community and then letting a computer generate a series of random numbers. If a 10% sample is needed, then the first 10% of the random numbers will indicate who will be the focus of the research. This sampling approach is reasonable for ethnographic research only when there does not seem to be much difference between the people in the population. Since this is rarely the case, random sampling is not often used for ethnographic research.
A stratified sample is one in which people are selected because they come from distinct sub-groups within the society. This is essentially what the U.S. Census Bureau does in its national census every 10 years. One member from each family is asked to answer for the entire family. This approach may be used by ethnographers as well if there are distinct, identifiable groups of people in the society and the information that is being sought is not specialized knowledge such as the esoteric activities of a secret organization with restricted membership.

Most ethnographers rely on a judgment sample . This is a limited number of key people selected on the basis of criteria deemed critical to the research questions. For example, religious leaders would be the focus if research concerns religious beliefs and practices. Likewise, talking mostly to women would make sense if the research concerned women's roles within society. The judgment sample approach works best if good informants can be found. These are people who are not only knowledgeable about their own culture but who are able and willing to communicate this knowledge in an understandable way to an outsider. Not everyone has the ability to do this. The quality of data usually depends on the relationships with informants. Ethnographers try to develop a warm and close relationship with their informants. This makes it more likely that they will learn what the host culture is really like.