Ziegler and Phillipson make a strong case for the need to reconsider traditional models of gifted education. Although their evidence and argument are compelling, the reviewers argue that several additional steps are needed to justify the theoretical foundation of the theory in order to facilitate its evaluation by researchers. First, Ziegler and Phillipson argue that most intervention studies in the field of gifted education show small effects, if any at all. Moreover, they criticize the field for its lack of control-groups and not following appropriate study designs. However, they then proceed to reject traditional approaches to gifted education even though its relevance or appropriateness has not been adequately evaluated. Although the reviewers are not arguing for the validity of traditional models over a new system-based approach, it is too early to reject traditional models without evidence of their inadequacies. A related-issue relates to measuring success in gifted education settings. For researchers, the concept of effect sizes and probability statistics provide appropriate benchmarks for determining the efficacy of specific relationships; however, these concepts may not have as much relevance to those working in the front lines of gifted education. For example, how does one determine the value of a program in gifted education? What benchmark provides a reasonable criterion for determining whether a program works? Moreover, determining the rate of success for an individual student is also problematic. The reviewers contend that there are many different facets of performance that can be evaluated during the learning process and it is clear that some effects only manifest later in development, making them hard to measure. Moreover, the criteria that determine proficiency during early development are often quite different from those determining long-term success in a given field of giftedness.