A large-scale test development project at the Language Teaching Research Center of the University of Gothenburg aims to develop tests in English as a foreign language for use in various areas of business and public administration. After testing, certificates stating current proficiency level in each of the four language skills (listening, reading, writing and speaking) will be given. Each person's knowledge of the language will be rated on a five-point scale. The project work involves correlation studies of the interrelationship between different parts of the test and between language proficiency and various intelligence factors. In one investigation an English language placement test was administered parallel to a battery of psychological tests covering analogies, opposites, verbal fluency, spatial ability and Pukort, a Swedish version of the Purdue Creativity Test. Personality tests measuring dominance, deliberateness, sociability, emotionality, flexibility, perseverance, emotional stability and independence were administered. Results show that certain relationships exist between language proficiency measures and personality and psychological variables. This should be considered when assessing foreign language mastery. (CHK)