This paper is a discussion of the methods employed by Quality Control (QC) Programmers, when performing QC by means of independent SAS® programming, for the most effective identification and reporting of discrepancies between a SAS Programmer/Analyst (SPA) and QC program set of results, with a given program specification. The discussion concerns both comparing the output of a program, that is SAS data sets, tables, listings, or graphic output, and on reviewing log files for coding issues and input data problems. Specific skills and traits are identified which are compatible with Good Clinical Programming Practices (GCPP) and the recently implemented 42 CFR Part 11 during the QC process. The content of this paper is based on many years of experience and past formal training of the author and of both current and prior project team members. Read More.