Randomized Experiments

In social science, a randomized experiment is a research study that seeks to determines the causal relationship between an independent variable and a dependent variable. This chapter summarizes types of randomized experiments, looks at the essential components of randomized experiments, and provides an example of such an experiment from the justice and prevention literature. The purpose of a randomized experiment is to determine the possible causal relationship between an independent variable and a dependent variable. The critical component of a randomized experiment is the random assignment process used to create the treatment and control groups. A randomized experiment is viewed as having strong internal validity but is criticized for lacking strong external validity. Experimental designs include randomized experiments, quasi-experiments, and natural experiments. Experimentation can be viewed as an ethical approach to keep an ineffective or potentially harmful treatment from being disseminated more widely. The chapter concludes with a description of challenges in implementing experimental designs.