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and links IR measurements to a ready made and well developed statistical theory,it has not found general acceptance amongst workers in the field
...Before proceeding to an explanation of the Swets model,it is as well to quote in full the conditions that the desired measure of effectiveness is designed to meet
...A desirable measure of retrieval performance would have the following properties:First,it would express solely the ability of a retrieval system to distinguish between wanted and unwanted items that is,it would be a measure of effectiveness only,leaving for separate consideration factors related to cost or efficiency
...He then goes on to claim that The measure I proposed [in 1963],one drawn from statistical decision theory,has the potential [my italics]to satisfy all four desiderata
...To arrive at the measure,we must first discuss the underlying model
...Recall an estimate of the conditional probability that an item will be retrieved given that it is relevant [we denote this P B A]...Precision an estimate of the conditional probability that an item will be relevant given that it is retrieved [i
...Fallout an estimate of the conditional probability that an item will be retrieved given that it is non relevant [i
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