Key points are not available for this paper at this time.
Merl Wittrock, a cognitive psychologist who had proposed a generative model of learning, was an essential member of the group that over a period of 5 years revised the Taxonomy of Educational Objectives, originally published in 1956. This article describes the development of that 2001 revision (Anderson and Krathwohl, Editors) and Merl's contributions to that effort.
Krathwohl et al. (2010) studied this question.