Representativeness and Bias in Cemetery Samples Implications for Palaeodemographic Reconstructions of Past Populations

Abstract

<p>This study examines the issue of representativeness with respect to palaeodemographic reconstructions from skeletal remains. Since determination of age and sex is fundamental to research in skeletal biology, it seemed warranted to examine the impact of representativeness and bias on interpretations based on these data. Mean age-at-death (MAD) is the primary statistic relied upon for interpretations of changing patterns of health and well being from palaeodemographic analyses. This study examines the issue of representativeness between skeletal samples and the cemetery population from which they are drawn. A series of sampling experiments conducted on three documented 19th century mortality sample distributions (St. Thomas' Anglican, Belleville, Union Cemetery, Waterdown, St. Luke's Anglican, Burlington) illustrates the danger in making interpretations based on mean age-at-death. It is proposed that whatever process mean age-at-death reflects in the health of past populations (fertility or mortality), it is irrelevant if the sample on which the statistic is calculated is not representative of the population. Given that most cemetery samples will be subject, differentially, to biases at a variety of levels, comparative studies based on palaeodemographic data cannot realistically be considered reliable without careful control for those biases. Without careful consideration of what or who exactly is represented by skeletal samples, palaeodemographic analyses shed little light on the realities of past life. If representativeness is, as I would suggest, the primary theoretical obstacle for researchers to overcome, then it is necessary to shift our focus to rigorously exploring those factors that bias our samples. Without some direct quantification of the representativeness of a sample, palaeodemographic estimators such as mean age-at-death are meaningless and any subsequent interpretations regarding the past, dubious at best.</p>