Research News You Can Use

Bryan G. Cook & Lysandra Cook

In the November, 2016 issue of Learning Disabilities Research & Practice, Linda Mason introduced a new “Research to Practice” series, which aims to explain critical topics in special education research with the goal of enabling practitioners to critically consume and apply research findings. The first article in the series (Cook & Cook, 2016) explored the issue of research design. Research design refers to how a research study is developed or planned. Studies are fashioned to answer different types of questions. Accordingly, when reading a study it is critical to understand its design to know what questions it seeks to answer.


Four common types of research designs in special education research are descriptive, relational, experimental, and qualitative. Descriptive studies (e.g., surveys, case studies, observational studies) are designed to describe phenomena. Although systematically describing issues such as the reading performance of students with learning disabilities and teachers’ attitudes toward inclusion are informative, it is important to recognize descriptive studies cannot tell us why findings occurred (e.g., why do teachers hold generally positive attitudes toward inclusion?) or the effect of the findings (e.g., how do teachers’ positive attitudes toward inclusion impact student learning?).


Relational research involves examining (a) the relation of two or more variables or (b) the difference between two or more groups on a variable. For example, a researcher might conduct relational research to examine (a) the relation between amount of professional development and teachers’ attitudes toward inclusion or (b) whether elementary and secondary teachers’ attitudes toward inclusion are meaningfully different. Although relational research provides important findings, these studies are not designed to establish causality. For example, even if relational research establishes teachers who receive more professional development have more positive attitudes toward inclusion, this type of study does not indicate whether professional development causes positive attitudes. Indeed, it is possible that (a) having more positive attitudes toward inclusion causes teachers to seek out more professional development; or (b) attitudes toward inclusion and teachers’ professional development are not causally related, and another variable underlies the observed relation (e.g., positive attitudes toward inclusion and higher levels of professional development might both be associated with teaching at elementary schools).


Experimental research is designed to reasonably establish that an independent variable controlled by the researcher (e.g., providing training on the legal and moral basis for inclusion) causes change in a dependent variable (e.g., teachers’ attitudes toward inclusion). Experimental research receives a lot of attention in special education because it establishes whether an instructional practice causes improved learner outcomes. One type of experimental study is a randomized controlled trial—in which researchers randomly assign participants to either a control group, which is taught using a “business as usual” approach, or to a treatment group, which is taught using the instructional practice being studied. If the researchers ensure the experiences of the two groups are the same except the presence of the treatment, then superior gains by the treatment group can be assumed to be caused by the treatment.


Single-case designs are another type of experimental study that establishes a functional relation between a treatment and learner outcomes. Despite their importance, experimental studies can be difficult and costly to conduct and do not answer many types of questions (e.g., they do not examine the impact of variables that cannot be manipulated by researchers, such as gender or disability type; they do not explore why or how one variable causes change in another).


Qualitative research encompasses a number of approaches (e.g., ethnographies, grounded theory, qualitative case studies) that examine words and phrases (rather than numbers) from sources such interviews, field notes, journals, and other documents. Qualitative researchers seek to provide rich and nuanced descriptions of individuals, events, issues, and relations between variables. For example, a qualitative researcher might conduct a series of interviews to explore why certain teachers hold positive attitudes toward inclusion. Although qualitative research can provide unique insights to the field, it is not designed to establish causality. For example, teachers enrolled in a study similar to the one mentioned above may misperceive how they developed their positive attitudes.


The take-away message from the article is “different research designs address different types of questions” (Cook & Cook, p. 197). Just as researchers need to use the appropriate type of research design to best answers their research questions, special educators should interpret research findings with the research design of the study in mind.  Careful consideration to the strengths and limitations of how the data was collected is critical when interpreting results.    This does not imply that some designs are better than others, it just means that different research designs answer different questions. We encourage interested readers to read the whole article at http://onlinelibrary.wiley.com/doi/10.1111/ldrp.12110/full.



Cook, B. G., & Cook, L. (2016). Research designs and special education research: Different designs address different questions. Learning Disabilities: Research & Practice, 31, 190-198. doi: 10.1111/ldrp.12110