The Structured Planning and Debugging Editor (SPADE) is a new kind of interactive programming environment in which computer programs are generated by explicitly articulating planning decisions. The design of SPADE is based upon the development of a grammar of plans from a taxonomy of basic planning techniques. The utility of this approach to program definition is that a record of planning decisions, called the plan derivation, provides guidance for subsequent modification or debugging of the program. Moreover, this grammatical approach to planning allows the development of a taxonomy of bugs, as particular kinds of errors in applying the planning grammar. Following a linguistic analogy, five types of planning bugs are characterized: syntactic, semantic, pragmatic, circumlocutions, and slips of the tongue. The plan derivation can be accessed during subsequent debugging to aid in diagnosing the underlying cause of erroneous code. Repair is accomplished via replanning, in which a substructure of the derivation is replaced. The design of a debugging assistant for the SPADE environment called RAID is based on this theory. Thirty references are listed. (Author/LLS)