TY - JOUR
T1 - Non-LIFO execution of cognitive procedures
AU - VanLehn, Kurt
AU - Ball, William
AU - Kowalski, Bernadette
N1 - Funding Information:
We would like to thank Jamesine Friend for conducting the experiment, and Austin Mnderson for writing the data collection program. Micki Chi, Paul Rosenbloom, Clayton Lewis and Stellan Ohlsson provided valuable comments on the manuscript. Micki Chi’s thoughtful advice was particularly important to the development of the research. This research was supported by the Cognitive Science Program, Psychological Sciences Division, Office of the Naval Research, under Contract No. NOOO14-88-K-0688. Reproduction in whole or in part is permitted for any purpose of the United States Government. Approved for public release; distribution unlimited.
PY - 1989
Y1 - 1989
N2 - Many current theories of human problem solving and skill acquisition assume that people work only on the unsatisfied goal that was created most recently. That is, the architecture obeys a last-in-first-out (LIFO) constraint on the selection of goals. This restriction seems necessary for the proper functioning of automatic learning mechanisms, such as production compilation and chunking. It is argued that this restriction is violated by some subjects on some tasks. In particular, 8 subjects (from a sample of 26) execute subtraction procedures in a way that violates the LIFO constraint. Although there is a great deal of between- and within-subject strategy variation in the 8 subjects' behavior, it can be simply explained by hypothesizing that (1) the goal selection is not necessarily LIFO, (2) goal selection knowledge is represented by explicit preferences, and (3) the 8 subjects have just a few preferences that are overgeneralized, overspecialized, or missing. The rest of their preferences are correct. On the other hand, LIFO-based models seem unable to explain the strategy variations in any simple way. Thus, it seems that part of the flexibility in human problem solving comes from having a choice of which goal to work on next. Fortunately, it is simple to ammend automatic learning mechanisms so that they will function correctly in a non-LIFO architecture.
AB - Many current theories of human problem solving and skill acquisition assume that people work only on the unsatisfied goal that was created most recently. That is, the architecture obeys a last-in-first-out (LIFO) constraint on the selection of goals. This restriction seems necessary for the proper functioning of automatic learning mechanisms, such as production compilation and chunking. It is argued that this restriction is violated by some subjects on some tasks. In particular, 8 subjects (from a sample of 26) execute subtraction procedures in a way that violates the LIFO constraint. Although there is a great deal of between- and within-subject strategy variation in the 8 subjects' behavior, it can be simply explained by hypothesizing that (1) the goal selection is not necessarily LIFO, (2) goal selection knowledge is represented by explicit preferences, and (3) the 8 subjects have just a few preferences that are overgeneralized, overspecialized, or missing. The rest of their preferences are correct. On the other hand, LIFO-based models seem unable to explain the strategy variations in any simple way. Thus, it seems that part of the flexibility in human problem solving comes from having a choice of which goal to work on next. Fortunately, it is simple to ammend automatic learning mechanisms so that they will function correctly in a non-LIFO architecture.
UR - http://www.scopus.com/inward/record.url?scp=38249023236&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=38249023236&partnerID=8YFLogxK
U2 - 10.1016/0364-0213(89)90019-0
DO - 10.1016/0364-0213(89)90019-0
M3 - Article
AN - SCOPUS:38249023236
VL - 13
SP - 415
EP - 465
JO - Cognitive Science
JF - Cognitive Science
SN - 0364-0213
IS - 3
ER -