Ideally materials at all levels should provide frequent exposure to authentic input which is rich and varied. In other worlds the input should vary in style, mode, medium and purpose and should be rich in features which are characteristic of authentic discourse in the target language. And, if the learners want to be able to use the language for general communication, it is important that they are exposed to planned, semi-planned and unplanned discourse (e.g. a formal lecture, an informal radio interview and a spontaneous conversation). The materials should also stimulate
Learner interaction with the input rather than just passive reception of it .This does not necessarily mean that the learners should always produce language in response to the input; but it does mean that they should always do something mentally or physically in response to it.