Anything which is used to help to teach language learners is called materials. Materials can be in the form of a textbook, a workbook, a cassette, a CD-Rom, a video, a photocopied handout, a newspaper, a paragraph written on a whiteboard; anything which presents or informs about the language being learned. The systematic appraisal of the value of materials in relation to their objectives and to the objectives of the learners using them. Evaluation can be pre-use and therefore focused on predictions of potential value. It can be whilst-use and therefore focused on awareness and description of what the learners are actually doing whilst the materials are being used. And it can also be post-use and therefore focused on analysis of what happened as a result of using the materials.