Proceedings of the Annual Meeting of the Cognitive Science Society

Children with a year of Logo programming were asked to think-aloud about the functino of some Logo recursive programs, and then to predict by hand-stimulation of the programs what the graphics turtule will draw when the program is executed. If discrepancies arose, children were asked to explain them. A prevalent but misguided "looping" mental model of Logo recursion persisted even in the face of contradictions between program effects and the child's predicitions.