Research Design - Design Types and Sub-types

Design Types and Sub-types

There are many ways to classify research designs, but sometimes the distinction is artificial and other times different designs are combined. Nonetheless, the list below offers a number of useful distinctions between possible research designs.

• Descriptive (e.g., case-study, naturalistic observation, survey)
• Correlational (e.g., case-control study, observational study)
• Semi-experimental (e.g., field experiment, quasi-experiment)
• Experimental (Experiment with random assignment)
• Review (Literature review, Systematic review)
• Meta-analytic (Meta-analysis)

Sometimes a distinction is made between "fixed" and "flexible" or, synonymously, "quantitative" and "qualitative" research designs. However, fixed designs need not be quantitative, and flexible design need not be qualitative. In fixed designs, the design of the study is fixed before the main stage of data collection takes place. Fixed designs are normally theory driven; otherwise it is impossible to know in advance which variables need to be controlled and measured. Often, these variables are measured quantitatively. Flexible designs allow for more freedom during the data collection process. One reason for using a flexible research design can be that the variable of interest is not quantitatively measurable, such as culture. In other cases, theory might not be available before one starts the research. However, these distinctions are not recognized by many researchers, such as Stephen Gorard who presents a simpler and cleaner definition of research design