You can read a brilliant article from the brilliant Adrian Underhill here on teaching without a coursebook, and I must say that I totally agree with him on this question. For a very long time I was obsessed with finding the right coursebook for my groups and students, but then I found myself in some strange teaching situations where I simply couldn’t or wasn’t ‘allowed’ to use books.
1.) ‘Madrelingua in classe’ project. You are sent to some elementary and middle schools to do conversational classes with 20-25 kids in the classroom. You cannot follow (and why would you?) their school book syllabus, and you are there with 25 kids and a blackboard. The school is not going to buy books for a 20-hour course, there aren’t any digital projectors around, no interactive whiteboards (even if the school had one, everyone would be scared to use it), and you can make only a limited number of photocopies.
2.) Top international bank in the centre of Milan. It is 5.30 in the evening. Lesson with the “Wealth Manager”. Really nice, intermediate-level student. Also very tired. He has done five different types of courses with ten different teachers, and he looks a bit doubtful when you try to introduce a new book to start another evening course. He is also ‘allergic’ to paper, traumatic childhood memories flooding over your student, making him look like a little boy again. You decide that you will be better off without a book for the course.
3.) Group course at international aviation company. Four engineers in a room. They have studied and worked in England, India, the USA, and they have also taken B2 and C1 level exams. They have been learning English for 15 years but their company decided to reward them for their results. Do these people want to start yet another C1 level course? Are they all at the same level? No-coursebook situation, again.
4.) Major language school in Milan. End of October. Young Learners course. Books ordered in September still nowhere. You have already had 5 lessons with your 8-year-olds. Apart from doing sample tests, would you start a new coursebook with unit 1, after having taught 5 lessons? Do authors actually know how much vocabulary these schoolkids know and use? You decide to order sample tests, and carry on without a coursebook, again.