The Quality Control (QC) Guidelines are intended to increase the efficiency, precision, and accuracy of the scoring, analysis, and reporting process of testing. The QC Guidelines focus on large-scale testing operations where multiple forms of tests are created for use on set dates. However, they may also be used for a wide variety of other testing situations and assessment techniques and for almost any situation in which assessment occurs. The QC Guidelines are applicable in any form of test administration, including paper and pencil tests and the ever-increasing computerized assessments via the Internet or offline. [This article was written for the International Test Commission (ITC).]