«Quantitative versus Qualitative Methods: Understanding Why Quantitative Methods are Predominant in Criminology and Criminal Justice George E. Higgins ...»
Journal of Theoretical and Philosophical Criminology, Vol 1 (1) 2009
Quantitative versus Qualitative Methods: Understanding Why Quantitative Methods are
Predominant in Criminology and Criminal Justice
George E. Higgins
University of Louisville
The development of knowledge is important for criminology and criminal justice. Two
predominant types of methods are available for criminologists’ to use--quantitative and
qualitative methods. A debate is presently taking place in the literature as to which of these methods is the proper method to provide knowledge in criminology and criminal justice. The present study outlines the key issues for both methods and suggests that a criminologist’ research questions and hypotheses should be used to determine the proper method.
Quantitative versus Qualitative Methods: Understanding the Methods in Criminology Research is the discovery of information that is either new or replicates previous findings.
Research becomes scientific when if follows specific methodologies that others may be able to replicate to arrive at similar results. Two types of methodologies are predominant in criminology and criminal justice that provide this sense of science--quantitative and qualitative methods. However, Tewksbury, DeMichele, and Miller (2005) have shown that quantitative methods are used more often than qualitative methods in criminology and criminal justice.
Importantly, quantitative and qualitative methods differ in several ways.
The present study contributes to the literature by presenting a theoretical treatment of quantitative and qualitative research. The study begins by presenting quantitative and qualitative Journal of Theoretical and Philosophical Criminology, Vol 1 (1) 2009 methods. Then, the importance of sampling to both methodologies comes. This is followed by discussions of the primary methodologies that are used in either approach. The data that are presented in each approach are presented. Then, the issues surrounding reliability of both methods are presented. This is followed by the discussion.
Quantitative and Qualitative Research Quantitative methods are based on the premise of empiricism and positivism (Rossi, 1994; Smith, 1983). These methods are rooted in the scientific method that is derived from the physical and natural sciences. Generally, these methods allow criminologists to be objective, formal, and systematic that arrives at a series of numbers to quantify phenomena (Creswell, 1994). That is, criminologists measure phenomena objectively affording them the opportunity to remain distant and be independent of the phenomena that is being researched.
This is consistent with the role of values in research. Using quantitative methods, research is able to be devoid of values. Values are removed from the research process because statements in written reports and instruments are removed (Babbie, 2002). Criminologists argue the “facts” of the study and not the values of the study. Criminologists that use quantitative methods write their reports in very specific ways. First, the reports are written impersonally.
This allows them to keep their distance and to make sure that their values are not interwoven into their research. Second, their reports are written in a formal tone with an emphasis on the connections, comparisons, and group differences between the concepts that are being studied.
For instance, Higgins (2007) presented a report that examined the psychometrics of a specific self-control scale. Importantly, this paper was written in a very formal tone that was removed of Journal of Theoretical and Philosophical Criminology, Vol 1 (1) 2009 values, but Higgins relied on the numbers to provide evidence to support or refute the hypotheses of the study.
The issues of concepts in quantitative research are important. Criminologists use theory to define their concepts and the connections between them. A theory is a set of interrelated or intercorrelated concepts and propositions that are designed to explain a behavior. In criminology, the behavior is typically criminal or deviant. Agnew (1995) argued that social learning, self-control, and strain theories were the leading general crime theories in criminology and criminal justice. Quantitative methods allow criminologists to be deductive in stating their hypotheses and research questions a priori from established theory, allowing criminologists to test theories and examine relationships for cause and effects. For example, Agnew (1992) argued that three forms of strain generate an emotion that prepares the individual to cope with the strain. In this example, three hypotheses are presented. The first is a direct hypothesis from the three forms of strain generating an emotion. The second is a hypothesis that emotion prepares an individual to cope. The third is implied and suggests that strain has an indirect connection with coping through emotion that may be conditioned by: criminal histories, peer association, or morality.
Qualitative methods are guided by ideas, hunches, or perspectives (Creswell, 1994;
Rossi, 1994). Criminologists that use qualitative methods are usually trying to develop theories rather than test them. In addition, the intention is to use the language of the subject to provide the understanding and not the quantity of the subjects. In other words, qualitative methods are subject (i.e., study respondent) driven and not theory driven. This allows criminologists to describe phenomena in a more humanistic and phenomenological view. Using an interview format, the qualitative researcher would focus on coping mechanisms and then proceed Journal of Theoretical and Philosophical Criminology, Vol 1 (1) 2009 backwards as to understand why the individual coped in a certain way. This is an example of subject generated research rather than theory driven research. The reason why the individual copes in this manner is induced and a theory is created for understanding. Qualitative criminologists will argue that their lack of dominance in criminology and criminal justice is due to the belief that the development of theory is secondary or invaluable. Quantitative criminologists recognize that falsifying the theories are far more important. To be clear, a theory derived from 10 to 15 research subjects needs to be examined across several thousand individuals or groups before it may be reified. This has been the case with the leading crime theories (i.e., social learning theory, self-control theory, and General Strain theory) (Agnew, 1995). It should be noted that these theories were not developed using qualitative methods, perhaps this is the reason why they have withstood multiple rigorous quantitative tests that transcend disciplines, races, ethnicities, and countries.
Qualitative methods allow criminologists to become part of the study by shortening the distance between him or herself and the research subject. Thus, they are typically the instrument allowing them to interject his or her values into the research (Babbie, 2002). This may occur in participant observation research where the researcher infiltrates a setting and participates in the activity so that they may gain access and acceptability among subjects. In this form of research, the criminologist really is the instrument and they are not able to take clear and concise notes during the interaction leaving a substantial amount of the information to memory. Redmon (2003) presents an example of this process. He collected interview data from individuals during Mardi Gras; however, Redmon is unclear about how the interview data were recorded. This leaves one to believe that he relied on his memory. If the interviews lasted between 10 minutes and 2 hours to complete the interview how could he possibly recall of the details from the Journal of Theoretical and Philosophical Criminology, Vol 1 (1) 2009 interviews. While this is not meant to diminish the contribution that this work has made in our field, it does illuminate the potential problems with this form of research. One of the strengths of quantitative research is the transparency that comes from the methods that are used to arrive at the findings.
The intention of qualitative research is not standardized and may change during the middle of study. This occurs in content analysis and interview data. Interview data provides an example of this issue. Maxwell (1996) argued that when performing interviews that the researcher should use “probing” questions to gain additional information about context. The problem with the “probing” questions is that they are often unscripted. This means that different subjects may get different versions of the “probing” questions that may provide different information. This is problematic when one considers that there is likely to not be an a priori presentation of the research problem and the categories that are used to capture them.
Quantitative methods attempt to add to the universal knowledge of society (Blalock, 1979). The use of experiments, surveys, and quasi-experiments has allowed criminologists to gain valuable insights into the criminal justice system and criminals. In criminology and criminal justice, these methods have been used to produce “real answers” from “hard data”.
Hard data in this instance is the use of numbers. Tewksbury et al. (2005) showed that “hard data” is the preferred method of criminologists. Qualitative methods have are generally not as good at giving direct answers, but are good at developing more questions. This occurs because qualitative methods are consistently using “soft data”. Soft data in this instance is language (i.e., body and words) to represent phenomena. Criminologists must consider sampling regardless of the method.
Journal of Theoretical and Philosophical Criminology, Vol 1 (1) 2009 Sampling Using either quantitative or qualitative methods does not absolve criminologists from the complexity of sampling. Regardless of the methodology being used, all of the samples have to be representative. To ensure that this takes place, quantitative methods require criminologists to use random sampling. However, when criminologists are conducting experiments, they are required to use random assignment (Babbie, 2002). Further, when criminologists are conducting quasi-experiments, they are required to use some form of matching technique.
When using quantitative methods, criminologists are typically guided by the central limits theorem to develop their samples. This theorem posits that when a sampling distribution begins to grow it will begin to appear like a normal distribution (Blalock, 1979). This allows criminologists to use their quantitative methods to generalize their results from their sample to the population. Unfortunately, criminologists are not always able to achieve a random sample, and this reduces the veracity that they can generalize their sample to the population. However, criminologists consistently do generalize their nonrandom sample results to their populations when they have large samples that appear large enough to satisfy the central limits theorem via the law of large numbers.
Qualitative methods have difficulty in the area of sampling (Berg, 2007). They may use the same strategies as quantitative researchers (i.e., random sampling: simple, systematic, stratified, or cluster), but qualitative researchers would have to contend with large samples that may not be specific to their research “hunch”. Qualitative researchers generally choose their samples from individuals or entities that are germane to the “hunch” that they have that is the impetus for the research. Generally, qualitative researchers have to contend with non-random samples that include the following: convenience samples (i.e., available subjects), purposive Journal of Theoretical and Philosophical Criminology, Vol 1 (1) 2009 sampling (i.e., researcher uses their special knowledge and expertise about the group to select the subjects), snowball sampling (i.e., the identification of several people with relevant characteristics, performing the qualitative assessment, and then asking them for names of others), and quota samples (i.e., researcher uses a matrix and then some non-random characteristic to fill the matrix).