The nature of the contents of the knowledge base is more than a little bit fuzzy. It certainly contains information about how to do things (i.e., procedural knowledge) and nonprocedural facts about the world (declarative knowledge) (e.g., Siegler, 1983). Although there is not an exact equivalence between procedural knowledge and strategies, the most important procedural knowledge considered in this book is memory strategies, which were considered in detail in the last chapter. Thus, the concern in this chapter is more on the declarative knowledge base and how it affects memory directly (i.e., through mechanisms other than facilitating the use of strategies as discussed in Chapters 3, 6, and 7).