A Tree: Planted and Growing

Background: Evaluation theory classification systems have been developed since the field’s early stages of theory development. Many have been published with the goal of promoting further understanding of the ways in which theoretical ideas relate both philosophically and in practice. This intends to promote a better understanding of the development and evolution of one of the classification systems, the Evaluation Theory, developed by Alkin and Christie first in the late 1990s and is in its most recent version, published in 2023. Purpose: This paper shares the primary purpose for developing the Evaluation Theory Tree, our analytic process for developing the categorization system presented as a tree, and how and why the tree has evolved over the years since its first publication.