In the Introduction I said that whether you were aware of it or not I suspect that you will have used self-instructional material in open, distance or flexible learning contexts. However, I suspect that you may be more familiar with writing technical reports, textbooks, book chapters, academic articles, etc. than self-instructional material. Indeed, I also suspect that you are very much aware that you typically adopt a particular style, format and language for the various documents you do write. But how do the style, format and language of a typical textbook differ from typical self-instructional material? If you are aware of these differences you will be more able to exploit them in your teaching or training materials. Below I have reproduced the question, offered the example of 'interest in the material' and provided you with space in which to note those differences you can identify.