n.a portion, within a body of records, selected for permanent retention through a statistical process that ensures each file within the series has an equal chance of being included in the retained setSly 1987, 60Indexing and cross referencing are an important subsidiary to arrangement. If the records were created with cross-referencing linkages, a probability sample would destroy that continuity, whereas a subjective sample could preserve them.Cook 1991b, 34Turning to probability sampling, which is the only kind of sampling recommended to archivists in this article, there are several required preconditions. To achieve statistical validity, it is highly desirable that a complete set of the records representing the entire population of the programme be available at the time the sample is taken. In other words, as formal sampling requires that all members of the population have an equal probability to be selected, the total population must be fixed and known.
