A statistical model for the response patterns to chemical tests for the absence or presence of trace materials

McKenzie, E. and Gettinby, G. and Lloyd, J. and Caddy, B. (1995) A statistical model for the response patterns to chemical tests for the absence or presence of trace materials. Science and Justice, 35 (1). pp. 31-36. ISSN 1355-0306 (http://dx.doi.org/10.1016/S1355-0306(95)72625-9)

Full text not available in this repository.Request a copy

Abstract

A statistical method is described which enables comparisons to be made between two sets of data where each datum can only be expressed as a positive or negative value. The method is based upon logistic regression analysis. It has been applied to patterns of positive and negative responses to chromatographic analyses carried out on hand swabs taken from a number of subjects suspected of handling explosives, and experimentally simulated data acquired on the basis of a contamination hypothesis. The analyses indicate that both patterns demonstrate ordering and that these orders are statistically indistinguishable.