In the previous five chapters I have examined some of the similarities and differences between research on everyday memory on the one hand, and laboratory studies on that topic on the other. In the next three chapters I consider some of the reasoning and judgment processes that operate on this knowledge and on information from the environment. Are the processes or skills involved in practical, everyday reasoning different from those involved in formal and/or academic reasoning, or are the processes the same but simply operating on different representations or databases (see Abelson, 1976b, for a similar distinction)? Can the results of lab research on reasoning and problem solving and from the psychometric study of intelligence be meaningfully applied to everyday reasoning? Are there differ-ences in reasoning processes and in knowledge representations between people who are more or less expert at a given task? Are these skills general across tasks (i.e., across formal and informal reasoning tasks, or across different types of practical problems), or are they taskor domain-specific? It is these sorts of questions that I consider in this chapter.