Method for evaluating the quality of database search results by means of expectation value

摘要

A method for determining the probability that a biological molecule identification is random for a chosen significance level and for a particular experimental condition, the method comprising: (a) providing biological molecule identification search result scores for an unknown biological molecule; (b) determining the frequency of each score to provide a frequency distribution of the scores; (c) determining the score associated with the mean of the distribution; (d) selecting parameters, defined as p1 and p2, wherein p1 is a score within a 10% range of the score associated with the mean, and p2 is a score which is greater than p1 and which has a frequency 1-15% of the frequency of p1; (e) fitting the distribution into a curve between points p1 and p2; (f) choosing a test score; (g) extrapolating the curve to obtain an expected frequency of the test score; and (h) assessing the expected frequency of the test score to determine the probability that the biological molecule identification is random for the chosen significance level.