WHAT IS AN EXPERIMENTAL RESEARCH DESIGN

 WHAT IS AN EXPERIMENTAL RESEARCH DESIGN 

One of the key aims of experimental study design is the development of research with a high degree of causal validity (internal validity). Utilizing randomized experimental designs yields the highest levels of causal validity. The causal validity of results from quasi-experimental procedures is susceptible to a number of potential errors. However, new quasi-experimental methods that have been taken from fields unrelated to criminology provide similar levels of causal validity to experimental designs.

The planning phase of research is replete with difficult and crucial decisions. Researchers must decide which research questions they will attempt to answer, which theoretical perspective will serve as the basis of their investigation, how they will accurately and reliably measure key constructs, who or what they will sample and observe, how many people, places, or things they will sample to achieve adequate statistical power, and which data analysis techniques they will use. These problems are pertinent to all academic disciplines (exploratory, explanatory, descriptive, evaluation research). On the other hand, these problems are not often what people refer to when they use the term "research design."

At the core of what is meant by "experimental study design" is the production of research that is judged to have a high degree of causal (or internal) validity. At the foundation of the idea of causal validity is the accuracy of statements about the causal links between causes and consequences. For example, does variable 1 cause variation in variable 2? Or does variable 2 cause variation in variable 1? Or does variation in variable 3 cause variation in variables 1 and 2? And how strong is the association between the identified components that have a causal effect? Therefore, research that aims to explain or assess anything is concerned with research design in the sense intended in this article, but research that wants to explore or describe something is often not concerned with study design.

It is almost hard to overstate the relevance of obtaining findings regarding the causes of crimes in the subject of criminology. In a number of criminological debates, the issue of whether or not correlates of offending are causally related to offending is a central subject. Offending is correlated with a variety of factors, many of which are well-known: poor parenting, friends who engage in criminal activity, a history of criminal activity, a young age (i.e. adolescents and young adults), being male, deviant attitudes, and personality traits such as impulsivity and psychopathy, among others. The vast majority of criminologists agree on these criminal behavior correlations. However, "correlation does not imply causation." There is much debate within the field of criminology as to whether of these linkages are really causal in nature. The association between deviant peers and criminal behavior is possibly the most widely-discussed aspect of this issue. 

According to proponents of the social learning hypothesis, an individual's level of deviance will increase if they have a large number of personal encounters with criminals. Social control theorists, on the other hand, argue that this relationship is not causal; rather, they claim that the positive relationship between having deviant peers is the result of "homophily," which is the tendency for individuals to associate with others who are similar to themselves – the proverb "birds of a feather flock together." In a similar vein, perspectives disagree as to whether or not there is a causal relationship between prior and later transgressions. 

Due to the fact that a lack of self-control is the underlying cause of both past and future criminal activity, Gottfredson and Hirschi (1990) suggest that this link is false. Other theories, such as Sampson and Laub's (1993) age-graded theory of informal social control, assert that involvement in criminal activity and contact with the criminal justice system increases the likelihood of future criminal behavior because these experiences reduce bonding to important sources of informal social control.

Discussions with the inference of causality extend beyond the sphere of theory. Regarding the effectiveness or causal effect of different criminal justice-based interventions on various criminal behavior measures, there is a substantial amount of debate. Evaluations of interventions in the criminal justice system (such as reentry programs, drug court, and domestic violence programs) often reveal that program participants have lower recidivism rates than nonparticipants. However, the majority of evaluations fail to offer proof that the reported improvements were really caused by program participation.

In other words, research design is an essential issue in the discipline of criminology because it is feasible to establish causal validity and causal findings from research that has been meticulously designed and executed.