The researcher has widely used sampling throughout the research. Why sample? The most obvious answer is that in many instances an examination of an entire population (a census) is unrealistic. So for the sake of efficiency, the researcher has opted to draw a sample from this larger population. Although assembling such a large population would be problematic enough, one might also wonder how the polling would take place.
How many pollsters would be required to contact each person in the population? There exist two broad classes of sampling schemes: probabilistic and nonprobabilistic (Palys, 2008, 141).
In this research theoretical sampling is used. A hallmark of using this type of sampling strategy is that they are purposively chosen to accomplish specific goals related to the inquiry. In qualitative inquiry, the purposive nature of the choice is much more tightly bound to the framework or theory guiding the research effort. In neither qualitative nor quantitative work is mere convenience a sufficient purpose for assembling a sample (Patton, 2001, 36).
Many are quick to lump sampling methods into categories of probability and convenience. This represents a fundamentally incorrect understanding of the role of sampling in the larger research process. Whereas competent quantitative research relies on probability sampling, competent qualitative research is defined by purposive choices about what, when, and how to observe behaviours or characteristics of sample elements. Often, nonprobability samples are constructed to ensure a focus on atypical extreme cases that might be presumed to best support (or challenge) theories guiding (or being developed through) the study.
In this research, the investigators have used snowball sampling technique. Snowball sampling uses a small pool of initial informants to nominate other participants who meet the eligibility criteria for a study. The name reflects an analogy to a snowball increasing in size as it rolls downhill.
This approach to locating research participants is almost always used as a form of nonprobability sampling (although some epidemiological research applies techniques from social network analysis to variations on snowball sampling as a way to estimate the total size of populations). Snowball sampling is a useful way to pursue the goals of purposive sampling in many situations where there are no lists or other obvious sources for locating members of the population of interest, but it does require that the participants are likely to know others who share the characteristics that make them eligible for inclusion in the study. This method is particularly useful for locating hidden populations, where there is no way to know the total size of the overall population, such as samples of the homeless or users of illegal drugs.
This research employs maximum variation sampling. It can also be called purposive sampling. To say one will engage in purposive sampling signifies that one sees sampling as a series of strategic choices about with whom, where, and how one does one's research. This statement implies that the way that researchers sample must be tied to their ...