The following is a modified excerpt from Applied Qualitative Research Design: A Total Quality Framework Approach (Roller & Lavrakas, 2015, pp. 199-201), a qualitative methods text covering in-depth interviews, focus group discussions, ethnography, qualitative content analysis, case study, and narrative research.
- Sites to observe.
- People within sites to observe.
- Observational events (e.g., how often to revisit a particular site).
Addressing this question can be complex—a process of both art and science—or fairly straightforward. In the simplest case, the number of sites to observe and observation events will be dictated by the (1) breadth and depth of the research objectives, (2) breadth and depth of the target population, and/or (3) practical realities of the research (e.g., the accessibility of the target participants, financial resources, and time available to complete the study). If, for example, the research objective is to examine the implementation of new procedures at a county free clinic, the number of sites to observe is just one (the clinic) and the frequency of observations will be determined by such factors as the fluctuation in the patient load (i.e., the slow- and high-volume hours in the clinic) and level of procedural details the observer wants to capture.
A more complex situation arises when the focus of the research is on a broad target population such as consumers. For instance, ethnographic research to study how consumers shop for vitamins would most likely require many observations of the same or different individuals within a variety of retail environments (e.g., supermarkets, drug stores, and superstores such as Target or Walmart). As a consumer researcher, Mariampolski (2006) recommends that the ethnographer observe no less than 15 sites; however, it is the expansiveness of the research objectives and target population, as well as practical matters, that may ultimately serve as the prime bases in the decision of how many sites to observe and how often.
In addition to the number of sites to observe, the ethnographer also wants to carefully consider how many individuals as well as the “type” of individuals who will be observed. As an example, is the observer interested in studying everyone on staff at the county free clinic (e.g., the receptionist, the nursing assistants, the nurses, and the physicians), or are the new procedures under investigation only pertinent to one aspect of the clinic, such as patient registration and check-in?
For all ethnographic research, the overriding “goal is to get at the meanings behind the acts” (Berg & Lune, 2012, p. 197) as they relate to the constructs under investigation. Not unlike the decision of how many in-depth interviews are sufficient for a research study, an ethnographic researcher must consider the number of observations (site and individual) at both the design and fieldwork phase. Ultimately, the researcher wants “enough” observations to be confident that the range of variation in what is being studied has been captured by the observations; however, the number that is anticipated when developing the research design may need to be adjusted when in the field. If there is more variation than expected, the researcher will need to extend the number of observations; otherwise, the lack of additional observations may threaten the Credibility of the study by missing something important in the behaviors of interest. A study concerning visitor attendance to the state park, for example, may need to expand the number of observations originally planned to include unexpected variations in behavior that occur during different weather conditions. In turn, if there proves to be less variation than expected—for instance, if park visitors behave very similarly regardless of weather, demographics, or other factors—the prudent researcher will want to make an explicit decision about terminating the field period sooner than had been planned. The caveat is that, although the researcher’s confidence in the variations of behaviors being observed is important, the decision to either extend or cut short the observations may also boil down to the practical or logistical realities of the study itself (e.g., safety concerns for a researcher observing in a high-crime area of the city, travel plans that cannot reasonably be changed, other types of ancillary research such as in-depth interviews that are also being conducted for the study and whose timing cannot be changed, and meeting others’ expectations to complete the research as planned).
Although there may not be an exact way to decide how many observations to conduct, a Total Quality Framework approach guides the researcher towards explicitly addressing a number of questions while in the field to assess this issue:
- How well have the observations provided insight on the constructs of interest?
- Is it clear to the observer what has been observed? What is the extent of the ambiguity?
- At what level can the observer explain or anticipate variations in the observations?
- Does the observer’s reflexive journal reveal any biases or concerns with objectivity?
- Have the observations provided the necessary input to facilitate next steps (i.e., the ancillary methods such as in-depth interviews)?
Berg, B. L., & Lune, H. (2012). Qualitative research methods for the social sciences (8th ed.). Boston: Pearson.
Mariampolski, H. (2006). Ethnography for marketers: A guide to consumer immersion. Thousand Oaks, CA: Sage.