Automatic versus intuitive and impressionistic classification of Norwegian spearheads from A.D. 550–1100

Norwegian spearheads from the Merovingian and Viking periods were classified by an automatic multivariate statistical method (discriminant analysis) and the results compared to those of an intuitive (436 spearheads) and an impressionistic classification method (1199 spearheads), the latter based upon measurements of well‐defined attributes and results of x‐ray examinations. A set of measurements of each of 338 well‐preserved spearheads (prototype specimens) served as the basis for the automatic classification. A fair correlation (87.2%) was observed between the results of the automatic and the intuitive classifications. A less favourable correlation (64%) was observed between the results of the automatic and impressionistic methods, mainly due to many incomplete (poorly preserved) spearheads which were inadequately classified by the automatic method. Accordingly, the automatic method was regarded as inferior to the impressionistic. In high quality spearheads with pattern‐welded blades, decorated sockets, and homogeneous proportional attributes, however, a close correlation was observed between the automatic and the intuitive/impressionistic classifications. Most likely, these spearheads are derived from highly specialized workshops. The automatic classification method seems, therefore, useful in tracing manufacture from such workshops.