30. The system of claim 29 , wherein the ranking calculator is configured to calculate the interim ranking values in an iterative process that comprises calculating the interim ranking values in a calculation sequence, the system further comprising a sequencing module to determine the calculation sequence based at least in part on respective initial ranking values, with lower initial ranking values being earlier in the calculation sequence.
30. The system of claim 29 , wherein the ranking calculator is configured to calculate the interim ranking values in an iterative process that comprises calculating the interim ranking values in a calculation sequence, the system further comprising a sequencing module to determine the calculation sequence based at least in part on respective initial ranking values, with lower initial ranking values being earlier in the calculation sequence. 32. The system of claim 30 , wherein the sequencing module is further configured to determine the calculation sequence based at least in part on a document volume parameter that indicates a quantity of documents to which respective contributors contributed, the ranking calculator further being configure to calculate the ranking values in an operation comprising: determining that a plurality of the contributors have equal initial ranking values; and forming the sequence such that, of the plurality of contributors, those with higher document volume parameters are later in the sequence.