Students often learn as much from each other as they do from the teacher. Material should make it easy to divide the class into groups or pairs, to have conversations or roleplay, and to allow the students to interact with each other. It is easy to be insensitive in the area of cultural differences. It is important to avoid potentially offensive images. Material where women are consistently portrayed as subordinate should be rejected.
Some older material can still be very useful.
In general, however, much progress has been made in the teaching of ESOL in recent years. It follows, therefore, that more recent material is usually preferable if available. Material suitable for an advanced student will be beyond the beginner's comprehension. Material suitable for a beginner will lack challenge for an advanced student. It is essential that material matches the abilities of the student.