In modern research, the sampling procedures often constitute the core of a project’s subsequent success or failure. The representativeness of the sample considered, or lack thereof directly shapes the reliability of the results. When the sample is representative of the general population or the group it aims to display, assumptions and claims can be derived. This factor is affected by multiple variables, such as sample size, sampling procedure, and propensity to respond.
The sample size is derived based on how many people researchers believe they need to survey in order to obtain accurate results for a target group. Although it is generally assumed that bigger samples are more representative of the overall population, it largely depends on the research subject and the group’s own characteristics. Additionally, even the largest sample can be compromised by a non-random selection of participants that would skew the data in an unaccounted direction (Dörfler & Stierand, 2019). Consecutively, the majority of peer-reviewed research articles today rely on simple random sampling unless specified otherwise. This approach allows researchers to ensure a distribution of potential variables of influence is roughly equal to its ratio in the overall population.
In relation to bias, the propensity to respond provides another danger for the scientists wishing to ensure their sample is sufficiently representative. If a survey covers multiple demographics, they might display an uneven willingness to participate in the research. The absence of the non-responsive members’ input in the results complicates any potential generalization (Little, 2021). By logical extension, any conclusion derived from such a sample would be flawed, as the non-responsive bias affects participants on a group basis. Hence, since differences between respondents and non-respondents are systemic, scientists often attempt to factor additional incentives for the non-responsive groups into the research design.
References
Dörfler, V., & Stierand, M. (2019) Extraordinary: Reflections on Sample Representativeness. In Lebuda, I., & Glăveanu, V. (Eds.) The Palgrave handbook of social creativity research (pp. 569-584). Palgrave Macmillan.
Little, R. J. (2021). A note about the definition of response propensity for survey nonresponse. Journal of Survey Statistics and Methodology, 1(1), pp. 2–4.