A study is reported in which 7 children (2 girls and 5 boys, 11 to 12 years of age) with a year of LOGO Programming experience were asked to think aloud about how a LOGO procedure would work, and then to predict by hand-simulation of the programs, what the graphics turtle "pen" would draw when the program was executed. While all children made accurate predictions for programs at the first two complexity levels (procedures using only direct command to move the turtle and procedures using the iterative REPEAT command), no child made accurate predictions for either level of complexity involving tail recursive procedures or embedded recursive procedures. The children's problems with explaining embedded recursion are traced to two related sources: general bugs in their mental model for how lines of programming code dictate the computer's operations when the program is executed, and the particular control structure of embedded recursive procedures. The report concludes with a brief description of the need to teach program control structures, such as recursion, rather than expecting children to discover them on their own. (Author/THC)
For related documents, see IR 011 338, IR 011 340, and IR 011 359.
LOGO Programing Language; Recursive Programming
1 - Available on microfiche
Bank Street Coll. of Education, New York, NY. Center for Children and Technology.