Quasi-experimental design is a form of study which is used to measure the impact of certain variables on a targeted group of people without any kind of randomization in their selection. It has two kinds of variables namely, dependent variable and an independent variable which influences the initial dependent variable taken into consideration (Shadish, Cook, & Campbell, 2002).
Strengths of Quasi-experimental designs
Quasi-experimental design method is very much useful in carrying an analysis on a particular group with respect to a specific variable where the group cannot be pre-selected on random basis. It saves a lot of time as well as resources while analysing a group which is to be analysed is too difficult to control and handle. It has high external validity as the experiment is being conducted under controlled variables and there is no chance of fluctuation under these variables (Weisburd, Lum, & Petrosino, 2001).
Weaknesses of Quasi-experimental designs
Quasi-experimental designs does not include randomization and hence the statistical results are less valid internally and it does not exactly help to identify the causal results cannot be determined easily and accurately. It does not consider the behavioural factor that is to be involved in critical cases where the mental state and background of the person has to be considered for analysing the behaviour of the person. It does not consider various variables which are important for the analysis as it has is executed under extremely controlled condition with controlled variables taken into consideration (Weisburd, Lum, & Petrosino, 2001).
Experimental design for Criminal Justice Research
For criminal cases, there are a number of variables that are to be considered for analysing their behaviour and at the same time generalising the results of the experiment has to be observed (Dantzker & Hunter, 2006). Classical method of experiments, also known as true experimental design requires an environment to be controlled naturally which is extremely difficult while conducting a research experiment on criminals. Hence, in such situations, conducting the experiment by quasi experiment design is the best solution where experiment is carried out in a controlled environment which is maintained artificially (Weisburd, Lum, & Petrosino, 2001).
For a group of people, like in the criminal justice research Cases, it is beneficial to conduct research through quasi experiment design as it provides required external validity in the research. The manipulation of the variables taken into consideration can be dangerous and unfavourable while conducting a criminal justice research as they have a distinct and intensified psychology. Thus, using quasi experiment design is preferable as it does not permit changes in the variables (Dantzker & Hunter, 2006). It provides better results than the classic experimental design when specific variables are considered to analyse the behaviour and its influence on the criminals while carrying a criminal justice research. Criminal justice research requires security and highly controlled environment which is very well provided by quasi experiment design.
Dantzker, M. L., & Hunter, R. D. ( 2006). Quasi-Experimental. In M. L. Dantzker, & R. D. Hunter, Research Methods for Criminology and Criminal Justice: A Primer (pp. 103-105). Jones & Bartlett Learning,.
Shadish, W. R., Cook, T. D., & Campbell, D. T. (2002). Experimental and quasi-experimental designs for generalized causal inference. Wadsworth Cengage learning,.
Weisburd, D., Lum, C. M., & Petrosino, A. (2001). Does research design affect study outcomes in criminal justice? The Annals of the American Academy of Political and Social Science, 578(1), , 50-70.