After Ryle (1949/2000), experimental and cognitive psychologists traditionally parse the nature of knowledge into two forms-declarative knowledge (or knowing that) and procedural knowledge (knowing how). However, it has been argued (e.g., Polanyi, 1966/1983) that there is a third type of knowledge called “tacit” knowledge, that is not well incorporated by these former two types of knowledge. Broudy (1977) for example, has claimed that this form of knowledge, which he referred to as “knowing with,” is an especially important aspect of an individual’s knowledge base; it is of particular interest in terms of what the individual learns in school, and what the individual can bring to bear on novel problems. A more precise description of these types of knowledge should be the first order of business.