The next in our series of online feature stories in the latest issue of NRMCA's quarterly magazine, Concrete InFocus, is Variation in Concrete Performance Due to Testing - Part 11 of the NRMCA Concrete Quality Series. This article - available only online because it's not included in the magazine's most recent print edition - discusses variability due to acceptance testing and methods to improve the quality of acceptance testing, thereby reducing the overall variability of concrete strength.