The three main responsibilities of archives are to collect records, preserve them and make them accessible. The first challenge which archives face is the selection of records. Appraisal is in fact a kind of selection according to financial, administrative and archival values of records, in order to decide what should be permanently kept. Due to the relentless increase in the number of paper and digital records, this process is inevitable. Various archival theories have been proposed, among which some of the most important are reviewed in this article.
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