System and method for ranking search results within citation intensive document collections

A non-transitory computer-readable medium comprising program instructions, which, when executed by a processor, cause the processor to perform a method for calculating a normalized activity score to rank an identified document, the method comprising:

• identifying a stored document;
• determining a number of times the identified document was cited in a subject matter community of the identified document;
• determining a probability distribution that individual documents within the subject matter community are cited a variable number of times by other individual documents in the subject matter community;
• calculating a probability function by performing a regression on the probability distribution;
• calculating the activity score value according to an activity score function formulated as an inverse of the probability function such that the activity score function is defined by:
• Score
• ⁡
• (
• x
• )
• =
• k
• (
• a
• ·
• x
• α
• +
• 1
• )
• p
• ,
• wherein:
• Score(x) is the activity score value, k and p are constants, x is the number of documents citing the identified document, and a and α are learned from the regression on the probability distribution;
• and
• the activity score function is such that the activity score value is calculated according to a probability that the individual document in the subject matter community is cited a number of times greater than or equal to the number of times the identified document was cited in the subject matter community;
• weighing the activity score value by an age of the identified document;
• and
• storing in computer memory a ranking of the identified document based on the activity score value.