Jack R. Fraenkel,
San Francisco State University
Norman E. Wallen,
San Francisco State University
| Accessible population | The population from which the researcher can realistically select subjects for a sample, and to which the researcher is entitled to generalize findings.
|
 |
|
|
| Cluster sampling | The selection of groups of individuals, called clusters, rather than single individuals. All individuals in a cluster are included in the sample; the clusters are preferably selected randomly from the larger population of clusters.
|
|
|
|
| Ecological generalizibility | The degree to which results can be generalized to environments and conditions outside the research setting.
|
|
|
|
| External validity | The degree to which results are generalizable, or applicable, to groups and environments outside the research setting.
|
|
|
|
| Generalizing | See ecological generalizability; population generalizability.
|
|
|
|
| Nonrandom sampling | The selection of a sample in which every member of the population does not have an equal chance of being selected.
|
|
|
|
| Parameter | A numerical index describing a characteristic of a population.
|
|
|
|
| Population | The group to which the researcher would like the results of a study to be generalizable; it includes all individuals with certain specified characteristics.
|
|
|
|
| Population generalizability | The extent to which the results obtained from a sample are generalizable to a larger group.
|
|
|
|
| Purposive sampling | A nonrandom sample selected because prior knowledge suggests it is representative, or because those selected have the needed information.
|
|
|
|
| Random sampling | Methods designed to select a representative sample by using chance selection so that biases will not systematically alter the sample.
|
|
|
|
| Replication | Refers to conducting a study again; the second study may be a repetition of the original study, using different subjects, or may change specified aspects of the study.
|
|
|
|
| Representative sample | A sample that is like the population in terms of relevant characteristics.
|
|
|
|
| Sample | The group on which information is obtained.
|
|
|
|
| Sampling | The process of selecting a number of individuals (a sample) from a population, preferably in such a way that the individuals are representative of the larger group from which they were selected.
|
|
|
|
| Simple random sample | see random sample.
|
|
|
|
| Stratified random sampling | The process of selecting a sample in such a way that identified subgroups in the population are represented in the sample in the same proportion as they exist in the population.
|
|
|
|
| Systematic sampling | A selection procedure in which all sample elements are determined after the selection of the first element, since each element on a selected list is separated from the first element by a multiple of the selection interval.
|
|
|
|
| Table of random numbers | A table of numbers that provides one of the best means of random selection or random assignment.
|
|
|
|
| Target population | The population to which the researcher, ideally, would like to generalize results.
|
|
|
|
| Two-stage random sampling | A process in which clusters are first randomly selected and then individuals are selected from each cluster.
|
2003 McGraw-Hill Higher Education