Describing Populations and Samples in Doctoral Student Research
Authors: Casteel Alex , Bridier Nancy 
Published: May 2021

Aim/Purpose: The purpose of this article is to present clear definitions of the population structures essential to research, to provide examples of how these structures are described within research, and to propose a basic structure that novice researchers may use to ensure a clearly and completely defined population of interest and sample from which they will collect data.

Background: Novice researchers, especially doctoral students, experience challenges when describing and distinguishing between populations and samples. Clearly defining and describing research structural elements, to include populations and the sample, provides needed scaffolding to doctoral students.

Methodology: The systematic review of 65 empirical research articles and research texts provided peer-reviewed support for presenting consistent population- and sample-related definitions and exemplars.

Contribution: This article provides clear definitions of the population structures essential to research, with examples of how these structures, beginning with the unit of analysis, are described within research. With this defined, we examine the population subsets and what characterizes them. The proposed writing structure provides doctoral students a model for developing the relevant population and sample descriptions in their dissertations and other research.

Findings: The article describes that although many definitions and uses are relatively consistent within the literature, there are epistemological differences between research designs that do not allow for a one-size-fits-all definition for all terms. We provide methods for defining populations and the sample, selecting a sample from the population, and the arguments for and against each of the methods.

Recommendations for Practitioners: Social science research faculty seek structured ways in which to present key research elements to doctoral students and to provide a model by which they may write the dissertation. The article offers contemporary examples from the peer-reviewed literature to support these aims.

Recommendation for Researchers: Novice researchers may wish to use the recommended framework within this article when developing the relevant section of the dissertation. Doing so provides an itemized checklist of writing descriptions, ensuring a more complete and comprehensive description of the study population and sample.

Impact on Society: The scientific method provides a consistent methodological approach to researching and presenting research. By reemphasizing the definitions and applications of populations and samples in research, and by providing a writing structure that doctoral students may model in their own writing, the article supports doctoral students’ growth and development in using the scientific method.

Future Research: Future researchers may wish to further advance novice researcher knowledge in developing models to guide dissertation writing. Future studies may focus on other essential areas of research, including studies about recruitment methods and attrition strategies, data collection procedures, and overall research alignment. Additionally, future researchers may wish to consider evaluating doctoral student foundational knowledge about populations and samples as part of the research process.