n.an appraisal technique in which a portion of a body of records is chosen for permanent retention through a process that employs a preset pattern of selection to produce a sample of the wholeHindus, Hammett, and Hobson 1980, 8Because of these complex docketing systems, we reconsidered the use of random numbers and considered using systematic sampling based on last digits of docket numbers.Boles 1981, 127Used thoughtfully, the mathematics can be coupled with simplified sampling techniques, such as systematic sampling, to obtain, at minimal expense, samples of known properties.Peterson 1982a, 12Systematic [Sampling]. Selection by physical characteristic of filing scheme without regard to the substantive information in the selected files.Bradsher 1988, 106By the first week of March, Dollar’s team developed a methodology to appraise the FBI's records that involved systematic sampling to identify case files to be inspected. The archivists would examine the selected files and record their characteristics on a data collection sheet. . . A statistical profile of each classification would be developed from these sheets to aid in making appraisal recommendation.Ham 1993, 77Systematic sampling. This is a more straightforward, quicker, and less expensive method that should be used when the file is already organized in random order; that is, there is no importance to the way the files are numbered and/or filed. Examples include documents filed by Social Security number, a consecutive numbering system, or the date a case file was closed (assuming it is a random event).Lyle 2004, 8Common forms of systematic sampling include: alphabetical, numerical and chronological samples (i.e., taking every nth record in order of alphabet, number or date), and physical samples (e.g., the “fat file method,” where files are selected according to thickness).