Before selecting any measurement instrument the test user should always determine what it is he wants to know. A new instrument, The Assessment of Career Development (ACD), attempts to assess students' knowledge about jobs. One must, however, determine whether the content of the ACD is similar to the content of the career information system the students are using to learn about these jobs. The paper presents the method of determining whether the content of the ACD was valid for measuring knowledge of job information if the job information system utilizes the Roe Occupational Classification. The paper provides the test user with the information needed to assess an information system (if employing Roe's classification) and, also, the method of determining the significant proportional differences of test content and criterion for any comparison. (Author)