Define population, sample, and sampling distributions and identify each as either empirical or theoretical. Explain the difference between statistics and parameters. Define sampling error and explain how it affects efforts to generalize from a sample to a population. Define the central limit theorem. Describe the z and t distributions, including whether these are empirical or theoretical distributions and which one is appropriate depending on sample size.
A population is the entire universe of objects, people, places, or other units of analysis that a researcher wishes to study. Criminal justice and criminology researchers use all manner of populations. Bouffard, for instance, examined the relationship between men’s military service during the Vietnam era and their criminal offending later in life. Rosenfeld and Fornango assessed how effective order maintenance policing is at reducing robbery and burglary at the neighborhood level. Morris and Worrall investigated whether prison architectural design influences inmate misconduct. These are three examples of populations—male Vietnam veterans, neighborhoods, prison inmates—that can form the basis for study.