Has definitive, detailed and annotated bibliographies, with fully identified statistical data sources. Some of these criteria are more applicable to particular subjects than to others, and there are no doubt addition factors to be considered in some cases. However, the importance of choosing texts after some informed and rational examination of alternatives, cannot be denied. When choosing a text particular consideration should be paid to its readability, notwithstanding all arguments about the need to use the language of the discipline being taught and not some ersatz version. If students fail because they cannot read a set text, the book is being used for the purpose of selection rather than instruction.
Unreadable texts increase uncertainty in the minds of students.
Tolerance of uncertainty varies from student to student, but eventually all will give up reading if a text is too difficult. It follows that to choose a suitable text it is desirable to attempt to predict its readability and consider just what makes a text difficult. Unfortunately individual judgements have been shown to be unreliable, probably because of lecturers' differing academic experiences. It is strongly advised that judgements about the readability of texts are made in consultation with your colleagues. Even though trialling of texts is virtually impossible, by working together and paying attention to some specific factors, it is possible to extend and make more reliable your professional judgement.