An equally important finding was that, in addition to instructional condition and age,
record keeping was a significant mediating factor for success in producing the complete
combinatorial solution. The eighth-graders were more aware of their memory limitations,
as most kept records (90–100% in the instructional conditions). The fifth-graders were less
likely to anticipate the need for records. Those who did rely on memory aids were more
likely to produce the complete factorial combination