# Typology and seriation dating

### Archaeology Wordsmith

Seriation dating is a form of typology dating. Typology dating organizes objects according to physical characteristics in a specific time frame. In archaeology, seriation is a relative dating method in which assemblages or artifacts from Errors in typology result in errors in seriation: For example, if a certain design style had two peaks in popularity (bimodal distribution), this design style. Define typology and types and explain why archaeologists use Typology also has a function as a tool for the organisation of material by relative dating. This is called 'seriation' and allows for assemblages of artefacts to be.

In addition to temporal organization, seriation results may reflect assemblage differences in social status, age, sex or those resulting from regional variation or a combination of two or more of these factors.

The result is not a chronological sequence due to the selection of types, the ordering seems to start with extremely male hoards and ends with extremely female ones.

Three conditions for chronological seriation[ edit ] Doran and Hodsonp. Regional variation must be kept to a minimum, i.

The objects analyzed must all come from a single cultural tradition. The traits or attributes included in the seriation must depend on cultural aspects rather than on function. Statistical methods[ edit ] Development of seriation methods[ edit ] Nowadays, seriation results are no longer produced manually as in Petrie's times but by appropriate algorithms.

### Difference between typology and seriation dating? | Yahoo Answers

Though according to David George KendallPetrie's paper showed already a deep understanding of the mathematics of the seriation problem Quote: In Baxter'sp. Robinson based his frequency seriation method on a similarity matrix. InKendall proposed the use of multidimensional scaling techniques for seriation problems, and this approach has also been used by some other scientists see Baxterpp.

Baxter also presents a review of statistical methods for seriation and a description of these approaches pp. InDoran and Hodson pp.

- Typology (archaeology)
- Difference between typology and seriation dating?

Correspondence analysis for seriation purposes[ edit ] Today, the most popular seriation method both for contextual and frequency problems is based on correspondence analysis. The sequence of the first axis of a correspondence analysis is considered the best seriation order Shennan[4] p. Using this technique, not only the sequence of the objects but also those of the design styles is established.

Note that external evidence is needed to establish the direction of the sequence calculated, i. The resulting scatterplot showed the form of a horse-shoe where the graves were arranged on the curve according to their chronological order.

Similarly, a mapping of the component scores for the first two axes of the correspondence analysis result will display a parabola if the design styles considered are controlled by one factor only like chronology. This is called the arch effect by Hill and Gauch Therefore, it is recommended inspecting the scatterplot of the first two axes of correspondence analysis to find out if other factors play a role as well see Examples 2 and 3.

If more than one factor is important, the arch effect may distort the results. Hill and Gauch presented a method to remove this effect. InGroenen and Poblome adapted the correspondence analysis algorithm to combine seriation with absolute dates and stratigraphic relationships. Small contextual seriation[ edit ] The small example below was inspired by Flinders Petrie's serial ordering of Egyptian pottery as published by Renfrew and Bahnp.

Raw data for contextual seriation Result of contextual seriation Another way of presenting the raw data for contextual seriation: For example, consider the first column: A beaker is contained in contexts 1 and 2. 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.

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 graves studied by Petrie they are extremely helpful.

Simulated data, seriation and correspondence analysis[ edit ] The data presented in this example was simulated by WinBasp. Initially 60 contexts called units in WinBasp were created along with 50 types. The contexts were labeled in chronological order by numbers 01 to 60, the types are labeled in the form T to T If a type is represented by one object only this object is not relevant for the chronological sequence as it does not provide a link to another context.

Similarly, contexts containing one object only are irrelevant for seriation. Therefore, the contexts with one or no object and types represented by one object or not at all were eliminated. The resulting raw simulated data consisting of 43 contexts and 34 types are shown on the left. As expected, the dots indicating the occurrence of a type in a context are close to the diagonal of the table.

Raw simulated data for contextual seriation Result of seriation The image on the right hand side shows the result of the seriation for this data set. Note that the dots are even more compact along the diagonal of the table compared to the raw data.

### Typology (archaeology) - Wikipedia

This shows a minor problem of seriation: In fact, the intervals of production may be somewhat longer than those calculated by the algorithm. In general, the sequences of contexts and types calculated by a seriation algorithm are not the correct chronological sequences but they are fairly close. Hildebrand published a fundamental paper on the development of fibulae in the s using the typological method, whereas Montelius at the same time went to international congresses and published smaller papers on this method.

Another early example is the typology published in by Flinders Petrie for the objects mainly pottery found in prehistoric Egyptian graves. Statistical methods for creating a typology[ edit ] With the development of statistical techniques and numerical taxonomy in the s, mathematical methods including Cluster analysisPrincipal components analysiscorrespondence analysis and Factor analysis have been used to build typologies.

These techniques provide a qualitative way to articulate the degrees of consistency among particular attributes.

## Seriation (archaeology)

Correlation coefficients created by these methods help archaeologists discern between meaningful and useless similarities between artefacts. Ceramic typology[ edit ] For cultures that produced pottery, archaeologists invariably spend a great deal of time defining ceramic "types.

Ideally, the attributes used to identify types are ones that are identifiable with the naked eye, and are found on small fragments of pottery, so that the sorting of potsherds into types is quick and straightforward. By sorting potsherds in terms of types, archaeologists can examine a series of potsherds including those lying on a site surface and quickly suggest when and where the pottery was made.

By extension, they can estimate when a prehistoric site was used, whether there are any traded pieces, and so on. The names assigned to the ceramic types are arbitrary. In United States, the common practice is a two-part name, the first part being an arbitrary geographic reference and the second part providing a brief description of the pottery's most obvious design attributes. Thus, for example, the type "Flagstaff Black-on-white" was first defined using a collection from the vicinity of Flagstaff, Arizona, and its primary design attribute is the use of black paint on a white background.

Non-archaeologists should be aware of the limitations of ceramic typology. All such typologies are abstractions, and fail to describe all of the variability in an artistic tradition. Professional disagreement over specifics is common.

Changes in ceramic design did not happen overnight, and archaeological typologies tend to break continua of design evolution into arbitrary but highly useful units. Most archaeological dates are approximate. Non-archaeological typology as an art form[ edit ] In the middle of the twentieth century, German photographers Bernd and Hilla Becher [13] raised typology to an art form by photographing countless similar architectural features including water towers, workers' houses and industrial landscapes.

They documented their work in books.