Accurate estimation of human adult age has always been a problem for anthropologists, archaeologists and forensic scientists. The main factor contributing to the difficulties is the high variability of physiological age indicators. However, confounding this variability in many age estimation applications is a systematic tendency for age estimates, regardless of physiological indicator employed, to assign ages which are too high for young individuals, and too low for older individuals. This paper shows that at least part of this error is the inevitable consequence of the statistical procedures used to extract an estimate of age from age indicators, and that the magnitude of the error is inversely related to how well an age indicator is correlated with age. The use of classical calibration over inverse calibration is recommended for age estimation.

No abstract

Much of the data which appears in the forensic and archaeological literature is ordinal or categorical. This is particularly true of the age related indicators presented by Gustafson [1] in his method of human adult age estimation using the structural changes in human teeth. This technique is still being modified and elaborated. However, the statistical methods of regression analysis employed by Gustafson and others are not particularly appropriate to this type of data, but are still employed because alternatives have not yet been explored. This paper presents a novel approach based upon the application of Bayes' theorem to ordinal and categorical data, which overcomes many of the problems associated with regression analysis.

No abstract

No abstract

In recent years, archaeology has interacted more and more with the physical sciences. In particular, chemical analysis has been established as a significant contributor to science‐based archaeology. The principal applications include compositional analysis of natural and synthetic materials and residues to ascertain artifact manufacturing processes and use; chemical and isotopic studies of biological remains and identification of plant and animal residues to investigate ancient diet, nutrition, and resource use; the determination of geographical sources of procurement or production of materials to establish long‐distance contact or trade; and the processes governing preservation and decay of materials and scientific investigation in the context of conservation and restoration. This article explores the role of chemical analysis in archaeology and highlights the importance of the findings in contributing to our understanding of the past. In particular, taking examples from the last 200 years, it demonstrates that chemical analysis of archaeological materials is not a routine application but one thatmust be informed by a thorough knowledge of the archaeological context, degradative processes, and material – environment interactions. Case studies span a wide range of elemental, isotopic, and molecular investigations with a bibliography comprising nearly 200 publications.

Strictly reproducible syntheses of the trimorphs of composition Cu2CI(OH)3 , atacamite, paratacamite, and botallackite, have been developed. In syntheses involving direct precipitation, or reaction of aqueous solutions with solid phases, reliable results are obtained only if the temperature and time of reaction are carefully controlled. Botallackite, the rarest of the naturally occurring trimorphs, is a key intermediate and crystallizes first under most conditions; subsequent recrystallization of this phase to atacamite or paratacamite, or of the latter from the former, depends upon the precise nature of the reaction medium. The crystallization sequence indicates that paratacamite, as has long been suspected, is the thermodynamically stable phase at ambient temperatures. Spertiniite, Cu(OH)2 , can be reproducibly synthesized via one route in the non-commutative titration of aqueous copper chloride with aqueous sodium hydroxide solutions.

It is generally assumed that life expectancy in antiquity was considerably shorter than it is now. In the limited number of cases where skeletal or dental age-at-death estimates have been made on adults for whom there are other reliable indications of age, there appears to be a clear systematic trend towards overestimating the age of young adults, and underestimating that of older individuals. We show that this might be a result of the use of regression-based techniques of analysis for converting age indicators into estimated ages. Whilst acknowledging the limitations of most age-at-death indicators in the higher age categories, we show that a Bayesian approach to converting age indicators into estimated age can reduce this trend of underestimation at the older end. We also show that such a Bayesian approach can always do better than regression-based methods in terms of giving a smaller average difference between predicted age and known age, and a smaller average 95-percent confidence interval width of the estimate. Given these observations, we suggest that Bayesian approaches to converting age indicators into age estimates deserve further investigation. In view of the generality and flexibility of the approach, we also suggest that similar algorithms may have a much wider application.