On Apr 26, 2011, at 4:54 AM, Ton Long Hiep wrote: > As I read in the document "Search application developer's guide", the > confidence score is defined as follows: > "Confidence scores are calculated by first bounding the scores between 0 and > 1.0, and then taking the square root of the bounded number" > However, there is no formula how it is calculated. Could someone help me?
Lets say you have results with scores up to 500. Well, the confidence of the top result item will be 1.0. The confidence of a result item with score 100 will be sqrt(100/500) = 0.4. There's no top score, so confidence is a way to normalize and bound the unbounded. Think of confidence as a way to quantify how much better one result item is than another result item. > Regarding to fitness score, it is stated as follows: > "The fitness number does not include any quality settings that might be on > the document, and it does not use document frequency in the calculation" > However, when I do search, the keyword which I search exists in the document > but the document's fitness is still below 1. Could someone explain it for me? Fitness also normalizes between 0.0 and 1.0 but ignores quality (the inherent goodness value you can assign to a document) and it ignores IDF (inverse document frequency, which is used so more rare terms have higher impact on score). It's just a report on how well the given document matches the given query. The values will always be between 0.0 and 1.0 because the results are designed to "normalize" all values to that range. -jh-
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