n.Appraisala portion, within a body of records, selected for permanent retention when retaining the whole would be too burdensome to maintainLewinson 1957, 292This definition is broader than the ordinary definition in that it envisages an archival sample as one that may illustrate some aspect of Government work, rather than represent it; and it is broader than the statistical definition in that it requires no measurable reliability of the sample.Levine 1983, 33First and foremost is that no case file duplicates another; each one is unique. This does not mean, however, that each file should be retained. It does mean that great care must be taken to assure that a comprehensive and representative sample is preserved.Guptill 1985, 21–22Should the required information involve individual cases such as employment verification for pension eligibility purposes, all records of that type have equal value; however, samples could be sufficient where the information needed is procedural, explaining how something was done.Melvin 1992, 49In some cases, indiscriminate samples of material in generic topical files were selected. These files addressed a wide range of concerns, often within an agency’s jurisdiction, and often not requiring any significant action or comment from the senator. An example of such files to be sampled were [sic] those under “Executive Correspondence—Post Office—Mail Delivery Service.”Appraisala portion, within a body of records, selected for permanent retention through a random process that ensures each file within the series or one of its subseries has an equal chance of being included in the retained set; probability sample; statistical sampleLeahy 1940, 37–38As indicated above, scientifically selected samples, in one case amounting to fifteen per cent of the large quantity of one body of records, have been preserved in lieu of whole collections. In these two efforts to reduce the bulk of public records, it seems that American archivists, because of greater financial resources and perhaps greater adaptability, are pointing the way to their European colleagues.Cook 1991b, 27Sample: The choosing of items or files from a series in such a way that the items or files chosen are a reliable representation of the whole from which they were taken—or of a predetermined significant characteristic(s) or subset(s) of the whole. The result of “probability” sampling, as statisticians call this practice, is a statistically valid sample, the representativeness of which can be mathematically verified within an acceptable margin of error, in comparison to the original population.Audiovisual RecordsDigital RecordsPreservation and Conservationa measure of quality in the capture of audio data, expressed in kilohertzCreaden 2006, 36Where greater bit-depth in imaging allows for a larger color palette and therefore greater color precision in the digital scan, so in sampling of sound greater bit-depth allows for a larger spectrum of tones and therefore greater tonal precision in the digital sample.ARSC 2009, 5Sample rates are somewhat controversial; there is some disagreement in our field about the minimum acceptable values. The de facto standard sample rate for archival master digital copies, which we recommend, is 96 kHz. Lower sample rates may be acceptable under certain circumstances but this decision should be made by experts and fully justified.Lawa portion, within a body of records, reviewed to determine whether it is likely to contain information responsive to a legal requestKPMG 2012, 5The ability to carefully select a sample and infer from it the condition of the larger population with a high degree of confidence in the reliability of the inference has tremendous utility in electronic discovery.v.Appraisalto select, as part of appraisal, a portion of a body of records for permanent retentionLewinson 1957, 293The archivist is sampling when he selects for preservation a certain number of applications from among all applications, a certain number of case files from among all the case files of a court or board, or all the files of some regional offices from among the documentation of all the regional offices of an agency.Guptill 1985, 66–67Tender and bidding documents, borrower documents and other records considered as having no historical value in evaluating the project’s effectiveness were disposed. Although these project files were scheduled, the contents of each file were appraised individually, and architectural designs were sampled.Sly 1987, 58So, the question may not be whether to sample, but rather how to sample. Sampling techniques will depend on the type of records in questions, and it is valuable to remember that probability sampling is not necessarily the most useful sampling approach.Nelson 1997, 52Many archivists recommend that constituent mail and casework be sampled, asserting that the volume of mail can be reduced without damaging whatever research value there may be in such files.Appraisalto select, as part of appraisal, a portion of a body for permanent retention through a random process that ensures each file has an equal chance of being included in the retained set of recordsMcReynolds 1975As archivists we know that we, too, only preserve and protect a sample of the total record that describes the work of the creating agency. “The record” is never complete even with the best records keeping techniques and personnel . . . Archivists should be able to sample without undue anguish about the integrity of the records.Boles 1981, 127Unfortunately, many record groups an archivist might wish to sample do not bear identification numbers, or bear duplicate numbers, so that in practice, before the sample can be conducted, each item must either be labeled or checked for duplication of identifying number.Ham 1984, 20–21If the National Endowment for the Humanities provides the funding, some social scientists cum archivists will combine statistical sampling with compaction by electronic data storage. The Inter-University Consortium for Political and Social Research in Ann Arbor, Michigan, has requested a grant to sample Bureau of Labor Statistics records on the income and expenditure activities of American families in the years 1888 to 1936. Data from a stratified statistical sample will be put into a machine-readable data file.Kepley 1984, 237The term sampling as used in archival literature usually means either to cull from a large records series the most significant files or documents (subjective sampling) or to select statistically a small portion from a large universe that will accurately reflect all important aspects of the larger universe (statistical sampling).Audiovisual RecordsDigital RecordsPreservation and Conservationto capture audio data using a measure of sound quality expressed in kilohertzCLIR and LoC 2006, 32It was pointed out that good digital converters can now down sample 96 kHz to 44.1 kHz much better than they used to, with negligible loss of audio fidelity.Creaden 2006, 37, fn. 5Most original sources don’t exceed 15 kHz, and the theoretical rule of thumb in digitization of sound is to sample at twice that.
In some cases, a body of records is so large that the permanent retention of its entirety would be an unmanageable onus to an archives. When this occurs, archivists may decide to retain a portion of the whole, and the portion retained is called a sample. In the most common use of the term in archives, a sample may be statistically valid, semi-random, determined by a specific nonstatistical method, or consist only of those records that are deemed to be the most interesting and useful for research. In formal statistics, a sample must always be made so that any unit in the population or subpopulation being considered has an equal chance of being that sample, which accounts for the second sense of this term. A minority of archivists use this definition of sample and use it to distinguish between a statistically valid random sample and any other means of selecting a subset of a set of records for retention.A sample in the legal sense is a portion of a body of records, particularly digital records, that are identified as having the highest frequency of use of the key terms related to a legal request for records. This sense is used particularly in cases of legal discovery. As in the case in archives, the legal sense of sample has as its essential purpose the reduction of the burden of dealing with extremely large quantities of records.Sample, as employed in the creation of digital audiovisual files, refers to the degree to which the full spectrum of sound is collected (that is, sampled) and preserved in the resulting file.