BACKGROUND: Reliability cannot be achieved in a clinical laboratory through the control of accuracy in the analytical phase of the testing process alone. Indeed a "mistake" can be defined as any defect occuring during the testing process. In the analysis of clinical specimens, there are many possible preanalytical sources of error. Therefore, the application of quality system to laboratory test...

Preparation of this chapter was supported by National Science Foundation Grant no. 1024293 and a grant from the Brady Education Foundation awarded to ASL, and a National Science Foundation Graduate Research Fellowship awarded to EDS. Play is too often in the American crosshairs, with those who claim it is a waste of time on the one hand and those who claim it is crucially important to developme...