Issues in testing proficiency in languages for special purposes (LSP) are examined in the context of the development of an advanced oral test in Japanese for tour guides. The test, designed at an Australian university for use in the Australian tourism industry, was to be designed to evaluate both language proficiency and skills in appropriate guide-client interaction. The major issue involves the use of both language specialists and profession-specific specialists in development of test items and assessment criteria. It was found, during construction of the test, that attention to definition of real-world, non-linguistic criteria for assessment is essential, and that the best way to ensure test relevance is to involve representatives of the industry at all stages of test development. (Contains 15 references.) (MSE)