When are inspection and testing considered quality control and when are they quality assurance? These words are often used interchangeably and may be defined in contradictory terms. For purposes of this article, quality control signifies those specific tests and inspections made by the material producer that determine acceptability of a product. Quality assurance is taken to mean a complete program performed by the purchaser that includes not only quality control functions but also other elements such as: program scope and assignment of responsibilities, internal audits, notifications of deviation, corrective actions, control and calibration of test equipment, and surveillance and audits by others to establish assurance or reliability of the quality control functions. The inclusion of the various elements in a specific program will depend upon factors such as national and local codes, purchasing and project specifications, and regulatory agency requirements. All of the material producers who contribute to concrete construction have quality control programs of various degrees. A program may be only a benign visual determination or it may involve comprehensive testing. The selection and operation of a specific program are usually dictated by the enforcement of the law and tempered by the purchase price. There is a standing controversy on who should provide quality assurance for concrete construction. The three parties involved are the owner, architect/ engineer and contractor. In addition the testing laboratory, governmental agencies and suppliers of materials may be involved. The question posed is whether inspection and testing should be an extension of design responsibility or whether quality assurance can be assigned to the contractor. The preferred method is one in which the purchaser implements a comprehensive quality assurance program either by means of his own personnel or through a consultant. This requires not only an audit of the producers' and contractor's quality control endeavors but also a continuing program of surveillance and check tests. The size, strategic importance and function of the project should govern the extent of the program.