השוואת שיטות

	Contextual Seriation	Frequency Seriation
תחום	ארכאולוגיה	ארכאולוגיה
משפחה	Process / pipeline	Process / pipeline
שנת המקור	1899	1962
הוגה השיטה	W. M. F. Petrie (sequence dating); formalized as occurrence seriation by mid-20th-century quantitative archaeologists	Leslie Spier; James A. Ford (developed from W. M. F. Petrie's sequence dating)
סוג	Relative-chronology ordering of units by presence-absence of types	Relative-chronology ordering of assemblages by type proportions
מקור מכונן	Lyman, R. L., & O'Brien, M. J. (2006). Measuring Time with Artifacts: A History of Methods in American Archaeology. University of Nebraska Press. ISBN: 9780803280526	Lyman, R. L., & O'Brien, M. J. (2006). Measuring Time with Artifacts: A History of Methods in American Archaeology. University of Nebraska Press. ISBN: 9780803280526
כינויים	Occurrence Seriation, Sequence Dating, Incidence Seriation	Frequency Seriation Dating, Battleship-Curve Seriation, Proportional Seriation
קשורות	3	3
תקציר	Contextual seriation, also called occurrence or sequence seriation, is a relative-dating method that orders discrete archaeological units — typically graves or closed deposits — using only the presence or absence of artifact types within them. Its logic is the lifespan assumption: each type is introduced, used continuously for some span, and then disappears, so the contexts in which a type occurs should form an unbroken stretch of the sequence. By permuting the rows and columns of a presence-absence matrix until every type's occurrences cluster into a single contiguous block, the analyst recovers a one-dimensional ordering interpreted as time. The technique originates with W. M. F. Petrie's sequence dating of Egyptian predynastic graves and remains a standard tool for chronology where only incidence data, not abundances, are available.	Frequency seriation is a relative-dating technique that orders archaeological assemblages in time by the changing proportions of the artifact types they contain. Its premise is that any cultural type is introduced, gradually becomes popular, peaks, and then declines, so that the relative frequency of a type traces a single rise-and-fall curve through time. By rearranging the rows of a type-by-assemblage abundance table until every type's frequency forms one continuous unimodal sequence, the analyst recovers an ordering interpreted as chronological. Drawn as horizontal bars, these curves take the lens or 'battleship' shape that gives the method its popular name. Frequency seriation grew out of W. M. F. Petrie's sequence dating and was formalized for proportional data by mid-twentieth-century Americanists such as James A. Ford, becoming a backbone of culture-historical chronology before absolute dating was widely available.