Combination of relative dating and absolute dating techniques to create
He reasoned that the most accurate sequence would be the one where concentrations of certain design styles had the shortest duration across the sequence of papers (Renfrew and Bahn 1996, p. In addition, it is vital that the lifespans of the different design styles overlap. to form groups of objects belonging to the same design style is by no means trivial.Following these rules, an assemblage of objects can be placed into sequence so that sites with the most similar proportions of certain styles are always together (Lock 2003, p. Creating a typology frequently is the basis of a seriation.The raw data are stored in an unsorted binary contingency table indicating which design style can be found in which context by a star symbol.For example, consider the first column: context 3 contains the design styles blackrim, bottle, and handle. Contextual seriation sorts the design styles and the contexts in such a way that the star symbols are found as close as possible to the diagonal of the table.
The sequence of the first axis of a correspondence analysis is considered the best seriation order (Shennan 1997, p. Note that external evidence is needed to establish the direction of the sequence calculated, i.e.
In Europe, it has been used frequently to reconstruct the chronological sequence of graves in a cemetery (e.g.
Jørgensen 1992; Two different variants of seriation have been applied: contextual seriation and frequency seriation (Renfrew and Bahn 1996, pp. Whereas contextual seriation is based on the presence or absence of a design style, frequency seriation relies on measuring the proportional abundance or frequency of a design style.
Of course, for a small examples like this, no computer programs are needed to find the best ordering, but for larger data sets like the 900 graves studied by Petrie they are extremely helpful.
The data presented in this example was simulated by Win Basp.