1. A method performed by a device, the method comprising: identifying, by a processor of the device, a plurality of documents, where a first one of the identified documents is linked by a second one of the identified documents and the second document is one of a plurality of documents in an affiliated set of documents; calculating, by the processor, a first value for each document in the affiliated set of documents based on a ranking score of the document and a number of outbound links from the document; calculating, by the processor, a second value as a maximum of the first values for the documents in the affiliated set of documents; assigning, by the processor, a ranking score to the first document based the second value, where assigning the ranking score includes: determining whether the documents in the affiliated set of documents are weakly affiliated or strongly affiliated, and setting the amount that the second document contributes to the ranking score of the first document as a function that acts as a summation operator over the affiliated set of documents when the affiliated set is weakly affiliated and as a maximum operator over the affiliated set of documents when the affiliated set is strongly affiliated, where the function is defined as: 
 (CONTRIB(D 1 ) a +CONTRIB(D 2 ) a + . . . +CONTRIB(D k ) a ) 1/a , where CONTRIB for document D k represents an individual ranking score contribution for document k in the affiliated set, and a is defined as 1 ⅇ + ( 1 - ⅇ ) ⁢ γ , where e is a constant and γ represents a continuous measure of the affiliation of the documents in the affiliated set; and storing, by the processor, the ranking score.
12. The method of claim 1 , wherein assigning the ranking score to a particular document is based on the formula: α + β ⁡ ( ∑ i = 1 m ⁢ ⁢ SETCONTRIB ⁢ ⁢ ( S i , γ i ) ) , where α and β are predetermined constants, the sum is taken over m affiliated sets of documents that link to the particular document, and SETCONTRIB is the function (CONTRIB(D 1 ) a i +CONTRIB(D 2 ) a i + . . . +CONTRIB(D k ) a i ) 1/a i for each of the m sets of affiliated documents.