Data from the Raven’s Standard Progressive Matrices (RSPM) pre- and post-tests of reasoning
(n=1192; µ = 0.84) indicated a statistically significant difference (p=0.000) between
the pre- and post-tests scores, and between improvements in scores of the experimental and
comparison groups. The five sets of 12 problems (60 in total) were analysed separately to investigate
the levels of complexity of reasoning at which gains were made (the sets increase
progressively in difficulty from sets A to E). Analysis of variance (ANOVA) of the Raven’s
data indicated that the greatest differences between the experimental group’s and comparison
group’s mean gain scores were in sets A and B (p