title: Using segmented linear regression models with unknown change points to analyze strategy shifts in cognitive tasks.
abstract: Some years ago, Beem (1993, 1995) described a program for fitting two regression lines with an unknown change point (Segcurve). He suggested that such models are useful for the analysis of a variety of phenomena and gave an example of an application to the study of strategy shifts in a mental rotation task. This technique has also proven to be very fruitful for investigating strategy use and strategy shifts in other cognitive tasks. Recently, Beem (1999) developed SegcurvN, which fits n regression lines with (n - 1) unknown change points. In the present article we present this new technique and demonstrate the usefulness of a three-phase segmented linear regression model for the identification of strategies and strategy shifts in cognitive tasks by applying it to data from a numerosity judgment experiment. The advantages and shortcomings of this technique are evaluated.
authors.affiliation: Center for Instructional Psychology and Technology, University of Leuven, Vesaliusstraat 2, B-3000 Leuven, Belgium. koen.luwel@ped.kuleuven.ac.be
authors.forename: K
authors.initials: K
authors.lastname: Luwel
authors.forename: A L
authors.initials: AL
authors.lastname: Beem
authors.forename: P
authors.initials: P
authors.lastname: Onghena
authors.forename: L
authors.initials: L
authors.lastname: Verschaffel
mesh_terms: D001288:Attention; D006801:Humans; D016014:Linear Models; D010364:Pattern Recognition, Visual; D011340:Problem Solving; D011601:Psychophysics