ABSTRACT
The paper presented by George Burket was intriguing, to say the least. His use of my model of school learning (Carroll, 1963) prompted me to see whether I could push that model further in studying his data and his interpretations. I perceived immediately that in view of the very large sample sizes represented, his data afforded a rare opportunity to attempt to fit a precise mathematical model to aptitude and achievement data over multiple grade levels. I am happy to report success beyond what I could have hoped for. Even though, as Burket remarked, I had suggested that longitudinal data would be more appropriate for exploring the usefulness of my model, the cross-sectional data he presented proved to be quite satisfactory for this purpose. (I would still hope that the longitudinal approach could be tried someday, but for now, the cross-sectional approach will suffice.)
