The book is built around the theory that there are three kinds of knowledge - declarative knowledge of facts and concepts (knowing that), procedural knowledge ( knowing how) and structural knowledge of the relationships between facts and concepts, which the authors believe mediates between declarative knowledge and procedural knowledge. In other words, if we are to be able to use our declarative knowledge to solve problems we need to also have structural knowledge ( knowing why).
The book contains 23 different strategies for representing/assessing, conveying and learning structural knowledge. The strategies are organised around the purpose they are best used for. The procedure for employing each strategy is explained, along with examples and a summary of the key research related to the use and effectiveness of the strategy. Some of the strategies are merely variations of other strategies already described and a few of the strategies require the use of complicated statistical procedures and are therefore not practical for the average classroom teacher. Overall the book contains some very useful strategies, however.