Assessment occupies a prominent place in education. In a broad sense, the term ‘assessment’ may refer to virtually any action that is taken in order to assess learners' progress and their current skills, knowledge and attitudes. Assessment may, among other things, include observations, think-aloud protocols, self-assessment, peer assessment, portfolio assessment (all commonly covered by the term ‘alternative testing’) (Brown & Hudson, 1998; Bultynck, 2004; Genesee & Upshur, 1996; Van Petegem & Vanhoof, 2002) and the use of more ‘classical’ tests. This chapter focuses on the latter: tests that aim to measure to what extent a language learner can perform certain language tasks at a particular moment in time. The limited focus of this chapter is warranted by the fact that tests still constitute the bulk of most teachers' assessment practices around the world. Nevertheless, most of the ideas and principles we will advocate in this article can also be applied to assessment in the broader sense.

In an educational setting, tests are tightly linked to learning goals on the one hand, and the educational programme on the other (see also Chapter 1 in this volume). The relations between goals, tests and the educational programme are multidirectional. On the one hand, goals constitute the crucial point of departure for both education (curriculum design, choice of methodology, etc.) and testing.