Students in all four instructional conditions were evaluated in terms of their performance on homework, a midterm exam, a final exam, and an independent project. Each type of work was evaluated for memory, analytical, creative, and practical quality. Thus, all students were evaluated in exactly the same way.

Sternberg et al. (1996) performed a principal-components factor analysis and found a weak general factor, suggesting that the general factor of cognition is probably relevant only when a fairly narrow range of skills is measured, as is typically the case with conventional tests. They found that testing format had a large effect on results: multiple-choice tests tended to correlate with other multiple-choice tests, almost without regard to what they measure. Essay tests showed only weak correlations with multiple choice, however. These investigators further found that after they controlled for modality of testing (multiple-choice versus essay), the correlations between the analytical, creative, and practical sections were very weak and generally nonsignificant, supporting the relative independence of the various skills. All three skill tests—analytical, creative, and practical—significantly predicted course performance. When multiple-regression analysis was used, at least two of these skill measures contributed significantly to the prediction of each of the measures of achievement. Perhaps as a reflection of the difficulty of deemphasizing the analytical way of teaching, one of the significant predictors was always the analytical score. Most importantly, there was an aptitude-treatment interaction whereby students who were placed in instructional conditions that better matched their pattern of skills outperformed students who were mismatched. In other words, when students are taught in a way that fits how they think, they do better in school. Children with creative and practical skills, who are almost never taught or assessed in a way that matches their pattern of skills, may be at a disadvantage in course after course, year after year.

Thus the results of the studies involving the STAT suggest that the theory of successful cognition is valid not just in its parts but as a whole. Moreover, the results suggest that the theory can make a difference not only in laboratory tests, but in school classrooms as well.

More recently, the triarchic theory of cognition was tested with an adult population, using alternative measures of analytic, creative, and practical cognition from the STAT questions described above. Grigorenko and Sternberg (in press) administered measures of analytical, creative, and practical cognition to 452 women and 293 men between the ages of 26 and 60 in a large industrial city in Russia. The environment in Russia is characterized by financial, institutional, political, and societal uncertainty and instability. The investigators hypothesized that, in such environments, practical and creative cognition would play as important a role, if not a greater role, in the successful adaptation to the changing social context.