The actual requirements (stated or implied) play a central role. These will eventually be expressed in terms of attributes. It is not always a straightforward task to extract the requirements from the user. For this problem, we have sought inspiration from the area of software requirements analysis, but it should be kept in mind that there are differences, in that the end result of such an analysis should be based on `implementable primitives', whereas for evaluation purposes we aim at `measurable primitives'. The process of arriving at properly expressed requirements will be iterative (or at least conceptually recursive). The PTB supports this process by allowing the cumulative reuse of components and skeletons from previous evaluations. Section Requirements analysis for language engineering evaluation will address this problem.