Closing Essay: A Journey, Not a Destination

The author believes that a unified theory might provide ideas helpful for improving research; professional training and practice; and therefore, student achievement. Little attention was paid to how several variables might work together and there is little discussion regarding how they might work together. The author stresses that there are reasons why a comprehensive, coherent, and unified modeling and testing process can be applied to achievement production. The purpose of this article is to identify these reasons. (Contains 5 endnotes.)