applied research Practical research that may involve evaluating existing or proposed policies or programs.
archives A place, either physical or electronic, where records and other data are stored.
association (or covariance or correlation) One of three conditions that must be met for establishing cause and effect, or a causal relationship. Association refers to the condition that X and Y must be related for a causal relationship to exist. Association is also referred to as covariance or correlation. Although two variables may be associated (or covary or be correlated), this does not automatically imply that they are causally related.
attrition or subject mortality A threat to internal validity, it refers to the differential loss of subjects between the experimental (treatment) and control (comparison) groups during the course of a study.
authority knowledge Knowledge developed when we accept something as being correct and true just because someone in a position of authority says it is true.
case study An in-depth analysis of one or a few illustrative cases.
categorical/qualitative Two terms that are often used to describe variables measured at the nominal and ordinal level.
cause and effect relationship A cause and effect relationship occurs when one variable causes another, and no other explanation for that relationship exists.
Certificates of Confidentiality Certificates awarded by the U.S. Department of Health and Human Services to protect researchers from court orders to identify information or characteristics of a research participant.
chi-square test A statistical test that examines the association between two variables measured at the ordinal or nominal level.
classic experimental design or experimental design A design in a research study that features random assignment to an experimental or control group. Experimental designs can vary tremendously, but a constant feature is random assignment, experimental and control groups, and a post-test. For example, a classic experimental design features random assignment, a treatment, experimental and control groups, and pre- and post-tests.
cluster/multistage sampling A type of probability sampling in which large geographical areas are clustered, or divided, into smaller parts. From there, random samples of individuals or groups or locations are taken in successive or multiple steps. For example, breaking a state down into regions would be a form of clustering. From there, taking a simple or stratified or systematic random sample of schools from each cluster would be one stage of sampling. A next stage of sampling might be randomly selecting students from each randomly selected school.
common sense knowledge Knowledge developed when the information “just makes sense”.
comparison group The group in a quasi-experimental design that does not receive the treatment. In an experimental design, the comparison group is referred to as the control group.
compensatory rivalry A threat to internal validity, it occurs when the control or comparison group attempts to compete with the experimental or treatment group.
complete observation A participant observation method that involves the researcher observing an individual or group from afar.
complete participation A participant observation method that involves the researcher becoming a full-fledged member of a particular group; sometimes referred to as disguised observation.
concept A clear idea regarding a particular subject based on that subject’s characteristics.
confederates Individuals, who are part of the research team, used to speed up the events of interest when observations are being made.
construct validity Assesses the extent to which a particular measure relates to other measures consistent with theoretically derived hypotheses concerning the concepts/variables that are being measured.
content analysis A method requiring the analyzing of content contained in mass communication outlets such as newspapers, television, magazines, and the like.
content validity When the survey questions measure the full breadth and depth of the concept being studied.
control group In an experimental design, the control group does not receive the treatment. The control group serves as a baseline of comparison to the experimental group. It serves as an example of what happens when a group equivalent to the experimental group does not receive the treatment.
convenience sampling A form of non-probability sampling in which the sample is composed of persons of first contact; also known as accidental or haphazard sampling, or person-on-the-street sampling.
criterion-related validity An assessment to determine the strength of the relationship between the responses to the survey and another measurement, the criterion, to which it should be related if the measurement is valid.
Cronbach’s alpha A statistic used to assess the internal consistency/reliability of an index.
cross-sectional designs A measurement of the pre-test and post-test at one point in time (e.g., six months before and six months after the program).
CSI Effect Due to the unrealistic portrayal of the role of forensic science in solving criminal cases in television shows, jurors are more likely to vote to acquit a defendant when the expected sophisticated forensic evidence is not presented.
deduction The process of using a theory and its tenets to develop one or more specific hypotheses.
demoralization A threat to internal validity closely associated with compensatory rivalry, it occurs when the control or comparison group gives up and changes their normal behavior. While in compensatory rivalry, the group members compete, in demoralization, they simply quit. Both are abnormal behavioral reactions.
dependent variable The outcome variable; the variable dependent on what occurs with the independent variable.
diary method A data-gathering technique that asks research subjects to keep a diary, or written record, of their time participating in the research study.
differential police response Methods that allow police departments to prioritize calls and rapidly dispatch an officer only when an immediate response is needed (i.e., crimes in progress).
diffusion of treatment A threat to internal validity, it occurs when the control or comparison group members learn that they are not getting the treatment and attempt to mimic the behavior of the experimental or treatment group. This mimicking may make it seem as if the treatment is having no effect, when in fact it may be.
disguised observation When a researcher joins the group under study to observe their behavior but does not reveal his identity as a researcher or his purpose for being there.
edgework Refers to researchers going to the “edge,” or the extreme, to collect information on subjects of interest.
elimination of alternative explanations One of three conditions that must be met for establishing cause and effect. Elimination of alternative explanations means that the researcher has ruled out other explanations for an observed relationship between X and Y.
ethical relativism The belief that how we think about ethics varies from one time to another, one place to another, and from one person to another.
ethics Recognized rules of conduct that govern a particular group.
ethnographic research Relies on field research methodologies to scientifically examine human culture in the natural environment.
experimental designs Used when researchers are interested in determining whether a program, policy, practice, or intervention is effective.
experimental group In an experimental design, the experimental group receives the treatment.
face validity An assessment of the survey questions to see if on “face value” the questions seem to be measuring the concepts and variables they are supposed to be measuring.
field research Research that involves researchers studying individuals or groups of individuals in their natural environment.
gatekeeper A person within the group under study whom the researcher can use to learn about and access the group.
generalizability In reference to sampling, refers to the ability of the sample findings to generalize or be applied to the larger population. For example, let’s say the findings of a sample survey on attitudes toward the death penalty reveal the majority of the sample is in support of the death penalty. If the sample is a good representation of the population, the results from this survey can be generalized or applied to the population.
going native A challenge to field research in which the researcher loses her identity as a researcher and begins to identify more with her role as a member of the group under study.
Halloween sadism The practice of giving contaminated treats to children during trick or treating.
Hawthorne Effect Based on a study of worker productivity; refers to changes in behavior caused by being observed.
history A threat to internal validity, it refers to any event experienced differently by the treatment and comparison groups—an event that could explain the results other than the supposed cause.
hypotheses Statements about the expected relationship between two concepts.
illogical reasoning Occurs when someone jumps to premature conclusions or presents an argument that is based on invalid assumptions.
independent variable The variable that determines and precedes the other variable in time; also called the cause.
index A set of items that measures some underlying concept.
indigenous observer A person within the group under study who is willing to collect information about the group for compensation.
induction The process of applying what is known about one or a few cases to an entire group.
informed consent Voluntary consent required from competent research participants after participants have been given accurate and relevant information about the study regarding procedures and possible risks and benefits to participation.
institutional review board (IRB) A group of individuals selected to review research proposals to check compliance with federal and state law; determines whether research should be conducted based on a risk-benefit ratio.
instrumentation A threat to internal validity, it refers to changes in the measuring instrument from pre- to post-test.
interrater reliability A ratio established to determine agreement among multiple raters.
journalistic field research Field research conducted by journalists and used to write books or articles about a certain topic of interest.
logistic regression A multivariate statistical test that regresses the independent variables on a categorical dependent variable (e.g., convicted or not convicted, violent or not).
longitudinal Refers to repeated measurements of the pre-test and post-test over time, typically for the same group of individuals; the opposite of cross-sectional.
matching A process sometimes utilized in some quasi-experimental designs that feature a treatment and comparison group. Matching is a process whereby the researcher attempts to ensure equivalence between the treatment and comparison group on known information, in the absence of the ability to randomly assign the groups.
maturation A threat to internal validity, maturation refers to the natural biological, psychological, or emotional processes as time passes.
mean The average of a set of scores (e.g., the average score for an entire research methods class).
measures of central tendency Refers to a set of statistics that produces a single number to represent a larger set of numbers; includes the mean, mode, and median.
median The middle score of all scores.
meta-analysis A type of content analysis in which researchers quantitatively review, organize, integrate, and summarize the existing research literature on a certain topic.
methodology The techniques utilized to gather information or data for research purposes.
mode The most frequent score among a set of scores.
multivariate statistical tests Refers to a set of statistical tests that examine the relationships between multiple independent variables and one dependent variable.
myths Beliefs that are based on emotion rather than rigorous analysis.
N/n Letter utilized to denote population and/or sample size.
negative association Refers to a negative association between two variables. A negative association is demonstrated when X increases and Y decreases, or X decreases and Y increases. Also known as an inverse relationship—the variables moving in opposite directions.
non-probability sampling methods As opposed to probability sampling methods, non-probability sampling methods include those sampling techniques in which every member of the population does not have an equal chance at being selected for the sample.
observer as participant A participant observation strategy in which the researcher is known to the group and the researcher is there only to observe.
operationalization The process of giving a concept a working definition; determining how each concept in your study will be measured (e.g., the concept of intelligence can be operationalized or defined as grade point average or score on a standardized exam).
oral/life history Methods used to conduct case studies; similar to an autobiographical account.
Ordinary Least Squares (OLS) regression A multivariate statistical technique that regresses several independent variables on a metric dependent variable (e.g., number of violent incidents).
overgeneralization Occurs when people conclude that what they have observed in one or a few cases is true for all cases.
paradigm School of thought; way to organize information within a discipline.
participant as observer A participant observation strategy in which the researcher will participate with the group but his identity as a researcher is known.
participant observation strategies First used for social science in the 1920s, these research methodologies involve participation and/or observation with the group under study; there are four such strategies.
peer review A form of quality control most commonly related to academic journals; process by which submitted manuscripts are sent out to be reviewed by experts in the field to determine whether the manuscript is suitable for publication.
personal experience knowledge Knowledge developed through actual experiences.
physical trace analysis The examination of physical substances that have been created and left by individuals as they come in contact with their environment.
pilot program or test Refers to a smaller test study or pilot to work out problems before a larger study and to anticipate changes needed for a larger study; similar to a test run; also can provide a preliminary set of answers to a research question before a full study.
population A complete group; could be all students at a university, all members of a city, or all members of a church; a defining feature of a population is that it be complete.
positive association Refers to a positive association between two variables. A positive association means as X increases, Y increases, or as X decreases, Y decreases.
post-test A measure of the dependent variable after the treatment has been administered.
pre-test A measure of the dependent variable or outcome before a treatment is administered.
probabilistic An event or outcome is more or less likely when certain conditions are present or not present.
probability sampling methods As opposed to non-probability sampling methods, probability sampling methods include those sampling techniques where every member of the population has an equal chance at being selected for the sample. Such procedures increase the probability that the sample is representative of the population, and hence, that the results produced from the sample are generalizable to the population.
proportionate stratified sampling A sampling method in which each predetermined category of the sample is represented in the sample exactly proportionate to their percentage or fraction of the total population.
pseudonym A false name given to someone whose identity needs to be kept secret.
pure research Research conducted to achieve new knowledge in the development of a discipline.
purposive sampling As a non-probability sample, purposive sampling involves the researcher selecting a specific or purposeful sample based on the needs of the research. If a researcher was interested in the techniques of residential burglars, their sample would be focused only on such burglars.
qualitative research Research that is sensitizing or helps to develop a better understanding about a particular group or activity for which there exists little information; more descriptive and less numerical than quantitative research.
quantitative/metric Term sometimes used to refer to variables measured at the interval or ratio level.
quantitative research Research that involves a numerical measurement of some phenomenon.
quasi experiment Refers to any number of research design configurations that resemble an experimental design but primarily lack random assignment. In the absence of random assignment, quasi-experimental designs feature matching to attempt equivalence.
quota sampling Similar to convenience sampling, quota sampling does involve taking into account a known characteristic of the population. For example, if 50% of the population is female, and the researcher wants a 100-person sample to survey, the researcher must survey exactly 50 females in a quota sample. Once the quota of 50 females is met, no other females will be surveyed.
random assignment Refers to a process whereby members of the experimental group and control group are assigned to each group through a random and unbiased process.
random digit dialing A sampling process involving phone numbers where a computer randomly dials the last 4 digits of a telephone number in a given area code using a known prefix. Random digit dialing, in this way, can help remedy the problem of unlisted phone numbers or numbers for which there is no so-called phone book (e.g., cell phones).
random selection Refers to selecting a smaller but representative subset from a population; not to be confused with random assignment.
randomly drawn sample A sample for which each member of the population has an equal chance at being selected. Samples not drawn through a random process are those in which each member of the population does not have an equal chance at being selected for the sample.
range A measure of variation that is the distance between the lowest and highest score in a set of scores.
reactivity The problem of having research subjects change their natural behavior in reaction to being observed or otherwise included in a research study.
reliability Addresses the consistency of a measurement and refers to whether or not a researcher gets the same results if the same instrument is used to measure something more than once.
representativeness In probability sampling processes, when the smaller sample is an accurate representation of the larger population.
research The scientific investigation of an issue, problem, or subject utilizing research methods.
research methods The tools that allow criminology and criminal justice researchers to systematically study crime and the criminal justice system; include the basic rules, appropriate techniques, and relevant procedures for conducting research.
resistance to change The reluctance to change our beliefs in light of new, accurate, and valid information to the contrary.
response rate The number of people who respond to a survey divided by the number of people sampled.
sample A smaller part of a whole population.
sampling In probability sampling, the process of selecting a smaller group from a larger group, with the goal that the smaller sample accurately represents the total population, despite being smaller in number.
sampling error The percentage of error or difference in using a sample instead of an entire population.
sampling frame A complete list of the population that the researcher will use to take a sample. If the sampling frame does not include each member of the population, and hence is not complete, a researcher must question how those who are listed on the sampling frame differ from those who are not accounted for on the sampling frame.
scale A set of questions that are ordered in some sequence.
secondary data analysis Occurs when researchers obtain and reanalyze data that were originally collected for a different purpose.
selection bias Selection bias occurs when the experimental (treatment) group and the control (comparison) group are not equivalent. The difference between the groups can be a threat to internal validity or an alternative explanation to the findings.
selective observation Choosing, either consciously or unconsciously, to pay attention to and remember events that support our personal preferences and beliefs.
self-administered surveys The distribution of surveys for respondents to complete on their own; includes surveys distributed by mail, group-administered surveys, and surveys distributed via the Internet.
shield laws Laws extending government immunity from prosecution for not divulging confidential and anonymous research information in court.
simple random samples As a form of probability sampling, samples randomly drawn from a larger population. Although each member of the population has an equal chance at being selected for the sample, this form of sample cannot guarantee representativeness.
simulations Artificial research settings that have been carefully created so that their features mimic reality as much as possible.
snowball sampling Also called referral sampling, a non-probability sampling technique utilized when a researcher is attempting to study hard-to-access populations. In snowball sampling, a researcher makes a contact, and that contact refers another, and so on. Over time, the sample snowballs, or gets larger. Because there is no ready-to-use sampling frame for some populations (e.g., gang members), researchers must use contacts and referrals to get a sample.
social desirability bias When a respondent provides answers to survey questions that do not necessarily reflect the respondent’s beliefs but instead reflect social norms.
split-half reliability An assessment of reliability in which the correspondence between two halves of a measurement is determined.
spurious A spurious relationship is one where X and Y appear to be causally related, but in fact the relationship is actually explained by a variable or factor other than X.
standard deviation A measure of variation that provides an idea of the variation of all particular values of a variable compared to the mean of that particular variable.
statistically significant A relationship between variables, or a difference between variables, is statistically significant when it is larger or smaller than would be expected by chance. The minimum level at which a relationship is considered statistically significant is .05, meaning that in only 5 in 100 chances would the relationship or difference be this small or large.
stratified random sampling A form of probability sampling where several simple random samples are taken from a population that has been divided up into strata, such as age, race, gender, or any number of strata based on information about the population.
survey research Obtaining data directly from research participants by asking them questions; often conducted through self-administered questionnaires and personal interviews.
systematic random sampling Involves selecting every nth person (e.g., 5th, 10th, etc.) from a list; the starting point on the list must be chosen at random.
target population The population of interest for a particular research study (e.g., all prison inmates, all domestic violence arrestees).
telescoping When a respondent brings behaviors and actions that occurred outside the recall period into the recall period.
testing or testing bias A threat to internal validity, it refers to the potential of study members being biased prior to a treatment, and this bias, rather than the treatment, may explain study results.
test-retest reliability An assessment of reliability in which a measurement is reliable over time if the same measurement is repeated using the same subjects and yields the same results.
theory A statement explaining how two or more factors are related to one another.
threat to internal validity Also known as alternative explanation to a relationship between X and Y. Threats to internal validity are factors that explain Y, or the dependent variable, and are not X, or the independent variable.
timing One of three conditions that must be met for establishing cause and effect; timing refers to the condition that X must come before Y in time for X to be a cause of Y. While timing is necessary for a causal relationship, it is not sufficient, and considerations of association and eliminating other alternative explanations must be met.
tradition knowledge Knowledge developed when we accept something as true because that is the way things have always been (so it must be right).
treatment A component of a research design, it is typically denoted by the letter X. In a research study on the impact of teen court on juvenile recidivism, teen court is the treatment. In a classic experimental design, the treatment is given only to the experimental group, not the control group.
treatment group The group in a quasi-experimental design that receives the treatment. In an experimental design, this group is called the experimental group.
t-test A statistical test that examines the level of association between two interval or ratio level variables (e.g., a t-test can examine whether the difference in final test scores between two classes is significantly different).
unit of analysis Refers to the focus of a research study as being individuals, groups, or other units of analysis, such as prisons or police agencies.
unobtrusive A method that is nonreactive; indicates that what or who is being studied is unaware of its/their role as research participant.
validity Addresses the accuracy of the measurement and refers to the extent to which researchers’ measure what they planned to measure.
variable(s) An operationalized concept allowing for specific measurement; a concept that has been given a working definition and can take on different values (e.g., intelligence can be defined as a person’s grade point average and can range from low to high or can be defined numerically by different values such as 3.5 or 4.0).
variance Provides an indication of how much each individual value of a particular variable differs from the average of a particular variable.
vulnerable populations Regarding informed consent, those populations for which there are unique risks and a question of whether their consent is fully voluntary or not coerced; examples include prison inmates and terminally ill patients.