Refining correspondence analysis-based ceramic seriation of regional data sets

Ceramic seriation is one of the primary tools used by archaeologists to create chronologies, especially for surface survey data. In this article, we outline a bootstrapped approach to correspondence analysis-based seriation designed to help assess and improve the stability of relative orderings produced through such analyses. This procedure systematically identifies and removes small samples and sites with unusual samples, such as those with multiple components, which are not handled well by seriation and require secondary interpretation. Our approach combines data from multiple projects in the Zuni region of the American Southwest in order to gauge the effects of intraregional variation in ceramic distributions and reexamine prior interpretations of demographic change based on individual projects. This analysis highlights two previously unknown regional trends, including variation in the distribution of multicomponent sites and potential short-term depopulation of a significant part of the region. Based on this example, we further suggest that our method may be particularly useful in situations where little prior chronological information is available.     

GLASS TRADE BEADS FROM THE ENGLISH COLONIAL PERIOD IN THE SOUTHEAST,CA. A.D. 1607–1783

Abstract

The study of glass trade beads has contributed much to our chronological understanding of the colonial period in the Eastern Woodlands of North America. Indeed, this class of artifact has allowed archaeologists to identify and conduct research at important archaeological sites that never appeared in the European historical record. In the Southeast, the best chronological resolution established by current bead chronologies relates either to sixteenth- to mid-seventeenthcentury Spanish-traded bead assemblages or eighteenthcentury French-traded bead assemblages. There is a conspicuous gap, however, in glass bead chronologies associated with the seventeenth- and eighteenth-century English-Indian trade in the Southeast. In this paper, I address this gap by characterizing a large sample of trade beads (n = 35,309) found in individual mortuary assemblages recovered from a number of Southeastern Indian sites. This is the first time a regional synthesis of this scale has been conducted for the English colonial period in the Southeast. In order to begin to refine the bead chronology of this period, I also present the results of a quantitative seriation (using a technique known as correspondence analysis) of the same mortuary assemblages. While the results of this exploratory technique represent a preliminary stage in this process, they nevertheless identify a number of temporal trends that can be used to derive occupation date estimates for sites spanning the English colonial period in the Southeast (ca. 1607–1783).     

Attribute-Based Seriation of Postclassic and Early Colonial Sherd Collections from the Basin of Mexico

Abstract

Seriation of ceramic collections based on diachronic changes in formal and surface treatment attributes offers advantages over type-based approaches when dealing with small collections. Individual attributes may be recordable where types (constellations of attributes) are not, increasing the quantity of chronological information that can be inferred. In addition, different classes of attributes (e.g., decorative, formal, surface treatment) highlight distinct processes and changes related to pottery production, consumption, and use, and provide a basis for finer-resolution seriation results. This paper outlines a procedure for attribute-based seriation analysis by detecting time-sensitive attributes and assigning sherd collections to temporal phases using clustering and ordination techniques, crosschecked with discriminant analysis. The results indicate a five-phase sequence for Middle-Late Postclassic and Early Colonial period collections from the Basin of Mexico (ca. A.D. 1200–1625).     

THE PLACE OF CHRONOLOGICAL STUDIES IN ARCHAEOLOGY A VIEW FROM THE OLD WORLD*

This article deals with the univeral problem of chronological versus social change and discusses the methodological foundations and the scientific functions of chronological studies, exemplified by the Nordic Bronze Age, a classic example of the development of a chronological system. First the universal validity of the premises of typology and seriation are questioned. Secondly, there is a discussion of the chronological implications of the many possible relationships between the period of production, the period of use and the period of deposition of artefacts. Thirdly the foundations of chronological change is analysed and finally the place of chronological studies in the research process is discussed.     

The Unitary Association Method of Relative Dating and Its Application to Archaeological Data

The primary objective of relative dating techniques is to determine a reliable sequence of archaeological deposits. This task becomes more difficult whenever our research steps beyond individual sites to the study of intercommunity relationships because we need to develop some means of associating unconnected deposits in time. Radiocarbon dating, as a stand-alone method, cannot always be used to draw reliable correlations between sites. The relevance of archaeological dates, including absolute dates, relies ultimately on the determination of artifact or sample associations and their respective superpositional relationships. The Unitary Association Method of Relative Dating is an alternative to seriation methods that is less susceptible to spatial variation and offers analytical strengths needed for regional chronological analyses.     

Model studies in computer seriation

A computer model is described which generates artificial incidence matrices, with statistical properties similar to those of a Merovingian cemetery, but with a known chronological order.These matrices are used to test the effectiveness of various seriation procedures. Both permutation search and multi-dimensional scaling methods are investigated. The effects of various similarity matrix transformations are also discussed.     

Effective hydration temperature of obsidian: a diffusion theory analysis of time-dependent hydration rates

An estimate of effective hydration temperature (EHT) is needed for chronological use of obsidian hydration data. This paper describes a method for calculating EHT by the practicing archaeologist, replacing three techniques that are in general use today: estimates based on mean temperature, numerical integration of models of diurnal and annual temperature variations, and use of temperature cells. The hydration (or diffusion) coefficient of obsidian is a function of temperature and thus is time varying, while the classic quadratic law of hydration is not valid for time-varying diffusion coefficients. This paper presents a mathematical solution to the case of a time-varying hydration coefficient, based on diffusion theory, with a concise definition of EHT. It is shown that the results are not affected by concentration dependence in the diffusion coefficient. A computer program to compute the rigorous solution is described, and data are presented to explore the resulting range of variation. That use of the Lee equation to compute EHT is not appropriate for obsidian hydration studies is evident from the data presented. The effects of paleoclimatic variation are estimated, and an algebraic best fit equation and worksheet are provided as practical aids to the archaeologist.     

Causalité Historique et Contemporanéité Relative: De la Relativité Einsteinienne aux Sciences Historiques

The construction of historical frame of reference based on the distinction between and articulation of phenomenological and chronological times. As it relativises the notion of simultaneity and inverts its relation to causality, the special theory of relativity can induce analogous modes of reflection on the themes of “contemporaneity” in the history of art (Panofsky) and in epistemology (Bachelard). This “relativist” method, often misunderstood, sheds light on both historical and presentist methods.     

On the Statistical Significance of the Observed Map in Spatial Diffusion

This paper examines the problem of determining the statistical significance of an observed spatial distribution vis-à-vis a simulated pattern of the “Hägerstrand type.” It is argued that the sampling distribution for a Hägerstrand type simulator is multinomial. The diffusion model considered is logically equivalent to a multinomial experiment with independent assignment of adoptions to areal cells according to a probability distribution that remains fixed for a given time interval. Conventional tests for goodness of multinomial fit are thus appropriate.     

Exploring Roman Ritual Behaviours Through Plant Remains from Pannonia Inferior

The recovery of new plant remains from eastern Croatia are discussed here in order to determine their ritual significance and how this evidence may fit into chronological and regional observations on ritual plant offerings in the Roman world. Samples collected from inhumations, cremations and an altar dedicated to Silvanus Domesticus, dating from the 2nd to 4th centuries AD, are presented and show that a range of more ‘common’ plant remains, such as cereals and pulses, were an important part of ritual life. These results are also compared to the growing archaeobotanical data collected from shrine and cremation burials across Europe. Although the archaeobotanical data from the Croatian sites are limited, the increasing evidence of ritual plant use allows observations regarding the wider context of Roman social and religious change.     

Theory and practice in urban pottery seriation

The paper discusses the principles and a procedure for analysing urban archaeological sequences using pottery seriation. Interpretations of particular shapes of seriation curve are offered and the problem of residuality is confronted. The method is suggested as having direct relevance for the definition of stratigraphic events and historical activities on urban sites.     

Modeling Categorical Data with Chi Square Automatic Interaction Detection and Correspondence Analysis

For the past decade we have been concerned with the application of categorical data techniques to mobility and housing choice. In a previous issue of this journal we reviewed a number of these modeling techniques. We now extend that earlier work by introducing correspondence analysis as a geometric interpretative technique that fits in an intermediate position between CHAID and nested logit analysis. The method is illustrated on the same housing and tenure choice data as was used in the previous paper.     

The Aggregation Problem in Location-Allocation

Location-allocation solutions based on aggregate estimates of demand are subject to error because of a loss of locational information during aggregation. It is shown that any method to remove or reduce uncertainty must be solution-specific and therefore impractical, for both median and center classes of problems. The significance of the error is illustrated by simulation of solutions to a number of artificial and real problems. It is suggested that aggregation problems be specifically addressed in applications of location-allocation models, and possible methods are proposed.     

Partitioning chi-square for the analysis of frequency table data: an archaeological application

Archaeologists often wish to compare observed frequency distributions with expectations generated by a model. We describe a technique of partitioning chisquare which yields information about goodness of fit to a model and about homogeneity among populations simultaneously, and which is often superior to other commonly used methods of evaluating frequency data. The technique is demonstrated with data from the Upper Paleolithic rockshelter Le Flageolet I. The results suggest selective raw material use by the Aurignacian occupants.     

中国居民消费增长波动多尺度变化及趋势研究

采用经验模态分解(EMD)方法对1953-2009年中国居民消费增长率波动进行分解,得到其IMF分量及趋势分量RES,运用方差贡献率及相关性检验其周期变化,并利用Mann-Kendall非参数统计检验方法对增长趋势进行研究。结果表明:中国居民消费增长波动存在3年、8年和12.4年的准周期,以准8年周期为主,准3年周期次之;56年来居民消费呈波动增长趋势,1978年是其突变点,当年对外开放政策的提出极大促进了居民消费增长,1983年居民消费增长率超过临界直线,此后呈显著上升趋势。经济因素、居民收入水平和消费结构是影响中国居民消费增长波动的主要因素。     

Decline in firing technology or poorer fuel resources? High-temperature thermoluminescence (HTTL) archaeothermometry of Neolithic ceramics from Pool,Sanday, Orkney

The Neolithic ceramic assemblage from the multi-period coastal settlement at Pool on the island of Sanday, Orkney is unique because it stratigraphically spans both the earlier round-based (including possible Unstan bowls) and later flat-based (‘Grooved Ware’) traditions. High-temperature thermoluminescence (HTTL) analysis objectively demonstrates that ceramics from the earliest Neolithic layers have been consistently better fired compared to examples from later layers. We suggest two interpretations of these data: either firing technology declined with changing social structures and/or adoption of a different ceramic tradition or that there was greater pressure on fuel resource and management in the later Neolithic. Paleoenvironmental and chronological evidence indicate climatic deterioration in the later Neolithic, which adds further support to an interpretation of a poorer fuel resource at that time. In addition to studies of the HTTL signal, analysis of the ambient temperature modification of the TL signal has potential to support or evaluate dating evidence, and is readily applicable to optically stimulated luminescence (OSL) age data.     

An efficient interchange procedure for the archaeological seriation problem

This paper considers the archaeological seriation problem defined over incidence matrices. Two procedures adapted from interchange algorithms for the travelling salesman problem are described and tested on 31 problems extracted from the literature. The better of these two procedures consistently yields excellent solutions and appears to outperform previous algorithms.     

The evolution of anthropomorphism in the neolithic engraved plaques of Southwestern Iberian Peninsula: a systematic approach from phylogenetics

Engraved slate plaques are a common part of the grave goods found in the Late Neolithic-Copper Age I megaliths of the southwest of the Iberian Peninsula (~3500–2700 cal BC). These objects have received a great deal of attention, since they are the first symbolic figurines to have become widespread in the Iberian Peninsula (almost 4000 plaques are estimated to be known today). Most previous studies, even from different and opposing archaeological perspectives, have highlighted the anthropomorphic nature of these plaques. The hypotheses regarding the evolution of their anthropomorphism and possible function have been diverse, yet there is a noteworthy absence of taxonomical studies in which the diversity and stylistic sequence of these symbolic objects have been systematically approached. This paper puts forward several models for the evolution of the anthropomorphism of the engraved plaques, based on cladistics and occurrence seriation. The results are then analyzed in conjunction with the currently available chronological and stratigraphic information. The paper concludes with a proposal of the most probable typology and its sequence, leading to a better understanding of the diversity and evolution of the plaques. Beyond this particular phenomenon, this paper provides insights into the study of the evolution of the symbolic representation of the human figure, through the development of an innovative methodological protocol.     

Chronological discrimination of silver coins based on inter‐elemental ratios using laser ablation inductively coupled plasma mass spectrometry (LA‐ICP‐MS)

This paper details the application of a statistical method for the chronological discrimination of silver coins using counts per second trace elemental, inter‐elemental ratios. The statistical method described is based on a method that has been applied to similar archaeological materials to determine their provenance. The method makes use of the inter‐element association patterns of multi‐element analytical data determined using laser ablation‐inductively coupled plasma‐mass spectrometry (LA‐ICP‐MS). The majority of the 266 coins analysed for this study have already been successfully identified by their mint markings. The data from LA‐ICP‐MS analyses, together with what is known about the coins through visual identification, were used to discriminate the reigning sovereign, and in the case of Mexico, the year of minting, of individual coins within the elemental fingerprint of different mints. Subsequently, unidentified coins can be placed in the confusion matrix, and their trace element information used to identify their year of minting when compared with other, identified coins from the same mint. The interpretational statistical technique linear discriminant analysis (LDA) was used to explore an identification of year of minting of coins that have previously not been identified by other means based on a statistical comparison against a database of compositional analysis of silver coins of known year of minting.     

The Middle Stone Age of East Africa and the beginnings of regional identity

The history of research into the Middle Stone Age of East Africa and the present state of knowledge of this time period is examined for the region as a whole, with special reference to paleoenvironments. The known MSA sites and occurrences are discussed region by region and attempts are made to fit them into a more precise chronological framework and to assess their cultural affinities. The conclusion is reached that the Middle Stone Age lasted for some 150,000 years but considerably more systematic and in-depth research is needed into this time period, which is now perceived as of great significance since it appears to span the time of the evolution of anatomically Modern humans in the continent, perhaps in East Africa.