Lexikon

weight of eidence in general is a measure of evidence on one side of an issue as compared with the evidence on the other side of the issue, or to measure the evidence on multiple issues.

In the law: measure of credible proof on one side of a dispute as compared with the credible proof on the other, particularly the probative evidence considered by a judge or jury during a trial.

Medical diagnosis: weights of evidence is a quantitative method for combining evidence in support of a hypothesis. The method was originally developed for a nonspatial application in medical diagnosis, in which the evidence consisted of a set of symptoms and the hypothesis was of the type "this patient has disease x". For each symptom, a pair of weights was calculated, one for presence of the symptom, one for absence of the symptom. The magnitude of the weights depended on the measured association between the symptom and the pattern of disease in a large group of patients. The weights could ten be used to estimate the probability that a new patient would get the disease, based on the presence or absence of symptoms.

Environmental sciences: weights of evidence was adapted in the late 1980s for mineral potential mapping with GIS. In this situation, the evidence consists of a set of exploration datasets (maps), and the hypothesis is "this location is favourable for occurrence of deposit type x". Weights are estimated from the measured association between known mineral occurrences and the values on the maps to be used as predictors. The hypothesis is then repeatedly evaluated for all possible locations on the map using the calculated weights, producing a mineral potential map in which the evidence from several map layers is combined. The method belongs to a group of methods suitable for multi-criteria decision making.

Sources:

http://legal-dictionary.thefreedictionary.com/weight+of+evidence

http://www.ige.unicamp.br/wofe/documentation/wofeintr.htm