Demographics

Demographics as Variables in Research

Demographic information provides data regarding research participants and is necessary for the determination of whether the individuals in a particular study are a representative sample of the target population for generalization purposes. Usually demographics or research participant characteristics are reported in the methods section of the research report and serve as independent variables in the research design. Demographic variables are independent variables by definition because they cannot be manipulated. In research, demographic variables may be either categorical (e.g., gender, race, marital status, psychiatric diagnosis) or continuous (e.g., age, years of education, income, family size). Demographic information describes the study sample, and demographic variables also can be explored for their moderating effect on dependent variables.

The Nature of Demographic Variables

Some demographic variables are necessarily categorical, such as gender, whereas other demographic variables (e.g., education, income) can be collected to yield categorical or continuous variables. For example, to have education as a continuous variable, one would ask participants to report number of years of education. But to have education as a categorical variable, one would ask participants to select a category of education (e.g., less than high school, high school, some college, college degree, graduate degree). Note that a researcher could post hoc create a categorical variable for education if the data were initially gathered to yield a continuous variable.

Defining Demographic Variables

Researchers should clearly and concisely define the demographic variables employed in their study. When possible, variables should be defined consistent with commonly used definitions or taxonomies (e.g., U.S. Census Bureau categories of [Page 347]ethnicity). It is generally agreed and advisable that demographic information should be collected on the basis of participant report and not as an observation of the researcher. In the case of race, for example, it is not uncommon for someone whom a researcher may classify as Black to self-identify as White or biracial.

Selection of Demographic Information to Be Collected

Researchers should collect only the demographic information that is necessary for the specific purposes of the research. To do so, in the planning stage researchers will need to identify demographic information that is vital in the description of participants as well as in data analysis, and also information that will enhance interpretation of the results. For example, in a study of maternal employment and children's achievement, Wendy Goldberg and colleagues found that the demographic variables of children's age and family structure were significant moderators of the results. Thus, the inclusion of particular demographic information can be critical for an accurate understanding of the data.

Confidentiality

Respondents should be informed that demographic information will be held in strictest confidence and reported only as aggregated characteristics, not as individual data, and that the information will be used for no other purpose. If necessary, researchers may need to debrief participants to explain the purpose of requesting particular demographic information.

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