n.choosing, as part of appraisal, a subset of records based on their unusual or significant qualitiesPeterson 1982a, 13Exceptional [Sampling]. Selection of files on significant individuals, precedent-setting programs, landmark cases. ¶ Advantages: Can be justified, although with some difficulty. ¶ Usually saves files that will be most in demand by researchers. ¶ Disadvantages: Is not statistically valid. ¶ May give a false impression of what originally comprised the whole series, i.e., might distort the view of a “typical” case. ¶ Requires great substantive expertise. ¶ Needs relatively good prior identification and arrangement of files so that the exceptional cases can be located and pulled. ¶ Very closely linked to research fashions; highly susceptible to bias. ¶ Cannot control the size of the sample.Hunter 2020, 64In contrast, exceptional sampling seeks to identify and retain files on significant individuals and events, precedent-setting programs, and landmark cases. This type of sampling requires the greatest subject expertise on the part of the archivist. It also is the method most prone to second-guessing by researchers: they may not consider the same items to be important.Note 2021Exceptional sampling is a technique of selecting a subset based on unusual or essential qualities. Examples of criteria used for exceptional sampling include controversial subjects, notorious or famous individuals, and “firsts.” Although not statistically valid, exceptional sampling can frequently capture materials commonly requested by patrons.
