1. The document discusses principles of quality assurance in laboratory testing. It defines quality assurance as the overall program that ensures correct test results are delivered to the right person on time. 2. Quality control refers to measures taken during each test to ensure results are accurate and precise. This includes analyzing controls to verify the test is working properly. 3. Quality assessment involves external evaluation of a laboratory's performance through proficiency testing, allowing assessment of the effectiveness of the quality assurance and quality control programs.