7. A computer program product for a quality management system, the computer program product stored on a tangible computer-readable medium and including instructions that, when loaded into memory, cause a processor to carry out the steps of: assigning documents to different groups of operators, each group containing at least two operators, each operator belonging to at least two groups; making the documents that are assigned to a group, available to the operators in the group in order for each operator to type data in the documents assigned to the group, the different operators thus generating different versions for each document; collecting the versions of the documents typed by the different operators; statistically analyzing discrepancies between the different versions without human intervention and without comparing to a known transcription of the document; and based on the statistical analysis of documents assigned to groups and based on the assignment of operators to groups, estimating an average frequency of errors for each operator without knowing a frequency of errors for any specific document typed by that operator, the frequency of errors averaged over the plurality of documents.
9. The computer program product of claim 7 wherein each group of operators consists of a pair of operators.