Question: Survey evidence is often introduced in court cases involving trademark violation and employment discrimination. There has been controversy, however, about whether nonprobability samples are acceptable as evidence in litigation. Jacoby and Handlin (1991) selected 26 from a list of 1285 scholarly journals in the social and behavioral sciences. They examined all articles published during 1988 for the selected journals nd recorded

(1) the number of articles in the journal that described empirical research f om a survey (they excluded articles in which the authors analyzed survey data that had been collected by someone else) and

(2) the total number of articles for each journal that used probability sampling, nonprobability sampling, or for which the sampling method could not be determined. The data are in file journal.dat.

a. Explain why this is a cluster sample.

b. Estimate the proportion of articles in the 1285 journals that use nonprobability sampling, and give the standard error of your estimate.

c. The authors conclude that, because "an overwhelming proportion of recognized scholarly and practitioner experts rely on non-probability sampling designs," courts "should have no problem admitting otherwise well-conducted nonprobability surveys and according them due weight" (p. 175). Comment on this statement.