n.a portion, within a body of records, selected for permanent retention because it meets criteria for selection set by the appraisal archivist; a subjective sampleLyle 2004, 7The Dutch Ministry of Justice, for example, used a purposive sample of its one million personal files to select “files which are formed in deviation from the rules. Here, only the exceptions (around 3 percent of the total) to the common practice are preserved”. Unfortunately, purposive sampling is also highly prone to human bias and selection error. Through dealing subjectively with the appraisal process, one’s samples are skewed toward personal feelings and cannot be taken as representative of the whole.
A purposive sample has no random element to it. Instead, the archivist sets criteria that are characteristics of important records and then compares each file to those criteria to decide which records are retained. The purposive sample is not statistically valid, so it is used with relatively heterogeneous records as a way of separating the archival wheat from the nonpermanent chaff.