A topic in teaching science
Teachers often use textbooks as a tool to support or supplement (or sometimes even to direct) their teaching.
However, from the perspective of the textbook author, writing a pedagogic text can be seen as a kind of teaching – albeit teaching people indirectly though composing a text.
Books do not contain knowledge
It is often thought that textbooks contain knowledge. This model suggests that the author puts knowledge in the textbook, and the reader is able to acquire it by reading. But life is not so simple.
Although there are different views on exactly what knowledge is, it seems reasonable that knowledge requires a knower – only an entity capable of knowing can have knowledge. So although a book contains text and images it does not know anything, and arguably does not contain knowledge.
(Read more about 'Knowledge')
So what does a textbook contain? It comprises representations of the author's knowledge – representations in a symbolic language (words, graphs, cross-sectional diagrams, chemical equations, mathematical formulae, etc.)
This may seem to be a semantic distinction, but it is important because the representations of knowledge in a book do not give automatic access to that knowledge. The representations have to be decoded, interpreted, and that means that the reader needs to use their existing 'interpretive resources' (what they already know and understand, etc.) to make sense of the text. The reader has to construct an understanding, to re-construct the represented knowledge as best they can.
(Read more about the 'Constructivist perspective')
This is obvious if we think about some extreme examples. A very good chemistry textbook written in Spanish will not be readily understood by a student who has no Spanish. A textbook on molecular biology written for final year undergraduates is unlikely to give the average 12-year old access to much of the represented knowledge even if written in their language – this reader will lack the advanced terminology and the background ideas needed to make good sense of the text.
So, even if the author does a very good job of representing their knowledge – that does not ensure that a reader will be able to make sense of the book, and of they do they, may not make THE sense intended by the author. They may misinterpret – misunderstand the author's intentions.
The textbook as a pedagogic text
A textbook is a particular kind of text, as it is designed to teach – to support learning. Therefore the author of a textbook has a similar task to a teacher planning a lesson or scheme of work. We would therefore expect textbooks to be different form other non-fiction works such as research papers, reviews of research, or technical reference works which are usually written by experts for other experts in the same field.
A pedagogic text therefore needs to be designed with some of the same kinds of features that teachers use.
(Read about key ideas for teaching in accordance with learning theory)
These might include:
careful sequencing, simplification, reiteration, use of metaphor, simile, analogy, etc., review activities, complementary images, etc.
(Read about qualities of pedagogic texts)
