"If I have seen further, it is by standing on the shoulders of giants" (Isaac Newton)

    The building blocks of hypotheses are variables. A variable is anything that varies, changes, or has differences. Something that never changes is called a constant.  Science does not try to explain much by constants.  It relies on the study of variables.  Variables that only have two extremes are called attributes. In social science, we deal mostly with two types of variables: independent and dependent. Independent variables are those things thought to be the cause or bring about change in other variables. Dependent variables are those things changed or affected by independent variables, sometimes through other variables (often called intervening variables). Independent variables always come before dependent variables in time and space.

    Hypotheses are simply if-then sentences that can be categorized in certain logical forms, such as no difference (null hypothesis), associated difference, directionality of difference, and magnitude of difference. A good hypothesis implies all these in a single sentence, and the trick is to express them as briefly as possible and in simple English. Let's take a look at how this is done:

Differences in Variable A have no relationship to differences in Variable B (null hypothesis)

If Variable A changes, then Variable B changes, or
There is a relationship between Variable A and Variable B, or
Variable A affects Variable B (all examples of
associated difference, sometimes called
nondirectional hypotheses)

If Variable A increases, then Variable B increases, or
If Variable A decreases, then Variable B decreases (both examples of directional hypotheses)

but you can also have inverse relationships, such as
If Variable A increases, then Variable B decreases, or
If Variable A decreases, then Variable B increases

If Variable A increases by 2 points (12% or whatever), then Variable B increases by 3 points (or whatever) (magnitude of difference)

and, you can also have directionality with magnitude in an inverse relationship, as in

If Variable A decreases by 5%, then Variable increases by 3%

    The point is that the more specific you make your hypotheses, the better. Not only may you be able to use more powerful statistics, but you will be engaging in what is called confirmatory research, instead of what is called exploratory research. The more your topic has been previously researched by others, the more it is expected that you will use confirmatory research. Exploratory research is used only in previously uncharted areas, or by those who honestly don't know anything about their topic. You'll note that the last example above contains all the elements of previous examples, so you can always drop down to a less rigorous hypothesis, but you can't or shouldn't move up to a more specific one after you've already done your research. Also, the null hypothesis remains unstated or implied as no differences, no matter how complex your other (called alternative) hypotheses get. Technically, all statistical tests are tests of the null hypothesis first, which is rejected in favor of degrees of confidence in the alternatives.

    An important part of the research process that goes along with hypothesis formulation is constructing your operational definitions. These are definitions of your variables for research purposes. They are important so others can understand and replicate your research. Researchers need to define their variables very precisely, especially the dependent variables. If "crime" is your dependent variable, you need to be very precise about exactly what kind of crime you have in mind: violent crime; property crime; vice crime; etc.  Context is important for operational definitions.  You want the concepts they represent to be as close as possible to the original constructs that existed in the mind of the first person who came up with the idea (you are investigating) in the first place.

    Many different criteria can be found in the literature over what are the desirable qualities of a "good" hypothesis.  If you are a theoretician, then a scientific hypothesis is what you are after, and this will resemble (although not be exactly the same) as your scientific theory.  You must "test" your hypothesis before it has any implications for theory.  A scientific hypothesis that has not been fully tested is usually called a "working hypothesis."  A useful hypothesis (and utility may very well be the most desirable quality) will enable prediction, or at least reasoning.  It will allow you to explore, observe, ask and answer questions.  Some people like to call their hypothesis an "educated guess," but the word "conjecture" is more appropriate for something like this.  In the end, the "best" hypotheses usually stick pretty close to the original interpretation of the person that first conceived of the whole idea in the first place.   

For each of the following, indicate the correct variable type by IV for Independent Variable or DV for Dependent Variable:
1. If crime increases as a result of the full moon, then crime is what type of variable?
2. If juries are more likely to impose the death penalty on blacks who commit crime against white people, then being black is what type of variable?
3. If involvement in crime is inversely related to age, then age is what kind of variable?
4. If citizen attitudes toward police improve by 20% for every 5% decrease in crime, then citizen attitudes toward police are what type of variable?
5. If there is a strong association between alcohol abuse and spouse abuse, then spouse abuse is what kind of variable?
6. If risk of victimization is a function of lifestyle and absence of guardians, then lifestyle is what type of variable?
7. If microsocial strain, mediated by locus of control and lack of social support, creates conditions conducive to committing crime, then locus of control would be what type of variable?
8. If the corporate ethics climate and white collar crime are associated, then ethics climate is what type of variable?
9. If the number of handguns sold illegally is linked to the number of homicides committed annually, then number of homicides is what type of variable?
10. For two groups of inmates, one which is exposed to an educational program, and the other which is not, it is shown there are significant differences in rehabilitative outcomes, then educational program is what type of variable?

A. Construct 3 nondirectional hypotheses that relate to a criminal justice topic and make sense.
B. Construct 3 directional hypotheses that relate to a criminal justice topic and make sense.
C. Construct 3 inverse directional hypotheses that relate to a criminal justice topic and make sense.
D. Construct 3 magnitude with difference hypotheses that relate to a CJ topic and make sense. 

Author unknown (date unknown). Advice on Formulating a Hypothesis.
Blalock, H. (1982). Conceptualization and Measurement in the Social Sciences. NY: Free.
Campbell, J. P., Daft, R. L., & Hulin, C. L. (1982). What to study: Generating and developing research questions. Beverly Hills, CA.: Sage Publications.
Lasley, J. (1999). Essentials of Criminal Justice and Criminological Research. NJ: Prentice Hall.
Seltzer, R. (1996). Mistakes that Social Scientists Make. New York: St. Martin's.
Wikipedia Entry on Hypothesis

Last updated: July 17, 2011
Not an official webpage of APSU, copyright restrictions apply, see Megalinks in Criminal Justice
O'Connor, T.  (2011). "Hypotheses in Research," MegaLinks in Criminal Justice. Retrieved from http://www.drtomoconnor.com/3760/3760lect02.htm accessed on July 17, 2011.