Types of Data

Different problems require different methods, and all education researchers must understand the nature of the problems they study and the nature of the methods available so that data can be ethically gathered and reliable conclusions can be drawn. In general, education researchers may use either quantitative research methods or qualitative research methods. Quantitative methods are used to gather numeric data which are analyzed using statistical procedures to describe populations or to test hypotheses; qualitative methods are designed to gather narrative data which are interpreted to elucidate hypotheses. 

Quantitative data can be used to either describe populations or quantitative data can be used to establish correlations. Means, ranges, standard deviations, and similar statistics can be used to describe populations and those measures can be communicated using a variety of numeric and graphic representations. Descriptive statistics can be used—for example—to compare performance of different groups on the data from standardized tests that are so common in today’s schools. Inferential statistics can be used—for example—to establish a correlation between students who experienced an instructional practice and their graduation from high school. Questionnaires and surveys are popular tools for gathering quantitative data and so are checklists or inventories. Scales are useful for quantifying variation. Writing the instrument for quantitative data collection is critical to the success of any research, and researchers must ensure that it both gathers all relevant factors and is written in a language appropriate for the subjects.

In describing a variation of interviewing as a research method, education and social science scholar Irving Seidman (1998) captured the essential focus of qualitative research methods: “understanding the experience of other people and the meaning they make of that experience” (3). Anshelm Strauss and Juliet Corbin (1990) recognized that education and social science researchers may be unaware of the many factors that affect phenomena being studied and that a researcher who ignores important factors when designing instruments to collect quantitative data may introduce unintended bias into the research. These two observations support the conclusion that qualitative methods are appropriate for studying wicked problems in which researchers seek to document the perspectives and experiences of the participants. 

Seidman (1998) further suggested the language used by humans to describe experience is a very important source of data, and that textual data gathered through qualitative research methods can be used to explain social phenomena as well as quantitative data can be used to explain phenomena in the natural sciences. Several methods for gathering qualitative research methods have been used in education, and most include an active role for the researcher in collecting narrative data. Interviews (both of individual and of groups) and observation protocols are common as is document analysis. Qualitative data can be presented either as themes or in case studies. When presenting data as a theme, the researcher reads and rereads the narrative data to identify meaningful trends and connecting ideas. The researcher then explicates these themes with reference to the narrative data. When presenting qualitative data as a profile, the researcher selects important elements of the data and creates a narrative description of the observed or interviewed subject.


Seidman, Irving. 1998. Interviewing as Qualitative Research: A Guide for Researchers in Education and the Social Sciences, 2nd ed.. New York: Teachers College Press.

Strauss, Anshelm, and Juliet Corbin. 1990. Basics of Qualitative Research: Grounded Theory Procedure and Techniques. Newbury Park, CA: Sage Publication, Inc.