Abstract
GKS has become the first standard in computer graphics. Standardization offers advantages only if there is credibility in the standards definition and the products related to it. Certification of a graphics standard is a means to protect the aim of standardization, the users of standard products and to give guidance to implementors of the standard. As there was a real need for tools to test the adherence to the standard, experts in computer graphics and certification outlined a practical strategy for certifying the GKS implementations. This has been realized since 1983. As a result, there now exist a number of GKS test packages which are based on different testing methods. The test suite is applied by testing laboratories to test the conformity of implementations to the standard. This paper describes testing techniques for GKS and outlines some strategies that will be used for future standards in computer graphics. (AGD)