Does shape matter? A comparative study of the usage of calibrated sieves in the study of burned human bone from archeological and forensic contexts

Abstract

In recent years, the use of a set of sieves became a crucial part of the methodology in studies of burned human bone from archeological and forensic contexts. A set of three sieves (10 mm, 5 mm, 2 mm) is widely used in studies of burned human remains, particularly those from the British Isles, in order to determine bone fragmentation, following methodology proposed by Jacqueline McKinley (1993). Usually, mesh opening sizes are reported in methods; however, their shape is rarely mentioned. This study aims to analyze the potential impact of the sieve mesh opening shape on the results achieved. It was tested by sieving the human burned bones from ten cremation burials from two Polish archeological sites by using two sets of sieves (10 mm, 5 mm, 2 mm). The first had round openings, while these of the second were square. Furthermore, the intra-observer and inter-observer errors were computed to assess the significance of differences between the tested sets of sieves. The analysis of values obtained by using a distinct set of sieves revealed noticeable differences. Specifically, when comparing the results of sieving through square versus round mesh openings, the paired t-test yielded lower p-values than intra-observer error measurement. This finding suggests that the observed differentiation between two sets of sieves is less likely to be a result of random chance. However, it is important to note that the inter-observer error also showed statistically significant differences. This indicates that the sieving techniques may vary between observers, potentially impacting the results obtained. The diagonal of square mesh openings is proposed as the most probable factor causing differentiation. However, it should also be considered that the differences in the distribution of mesh openings and total sieving surfaces between square and round openings might also alter the results. In addition, the sieving surface has higher values for sieves with square mesh openings, which follows the pattern of a higher diagonal of mesh openings for square sieves. In conclusion, the shape of the mesh openings and their distribution on the surface of the sieves might have a significant impact on the results concerning burned bone fragmentation. Consequently, information about the shape of mesh openings should be included in the “Materials and methods” section, along with the specifications of the apparatus and the dimensions, as well as the diameter of the mesh openings.