Errors in Skilled Performance.

This report details work from the first year of a two year project on undetected errors in skilled cognitive performance. First, we present the theoretical background in which our research program is cast Andersons 1983 ACT theory of memory and skill acquisition. Second, we outline a Set of circumstance that we believe promote error making -- namely, long-term priming i.e., training on a subset of the universe of possible problem solution types, short-term priming i.e, presenting multiple surface structure instantiations of a single, deep structure problem type in succession, and working memory load i.e., presenting a concurrent secondary task that requires working memory capacity. These form the basis of our empirical work presented later. Third, we describe our methodology for detecting undetected errors -- that is, bow we are able to decide whether an error is in or out of a subjects 5 awareness. Fourth, we present our empirical work. One set of three studies finds evidence for general processing sequence memory. This is memory for the order of application of cognitive operations, and is independent of the actual items i.e., surface structures of problems subjects actually encountered.