Comment

John H. Bishop continues to persuasively make the case that the United States must increase incentives for students to focus time and energy on school work. The instrument he sees as powerful is a system of external examinations students must pass to obtain a high school diploma. This paper, which Bishop has written with Ferran Mane, Michael Bishop, and Joan Moriarty, examines the impacts of several types of external examination requirements on a variety of student outcomes.

I applaud the Bishop team for its attempts to inform the debate about the consequences of standards-based reforms--a debate that has been characterized by more heat than light. The use of test score evidence from the National Assessment of Educational Progress (NAEP) and the National Education Longitudinal Survey (NELS), tests that do not involve stakes for students, is particularly valuable. Critics of studies showing improvements in scores on state-mandated tests argue that the gains do not show up in NAEP scores. The Bishop, Mane, Bishop, and Moriarty study does not have this limitation.

Overall, I find persuasive the argument Bishop and his colleagues make. This should not be surprising because, like Bishop, I have been trained as an economist and the idea that incentives matter lies at the core of economics. Students will not learn more unless they devote more time and energy to improving their skills. Teachers' efforts to improve student skills are often watered down by multiple demands. External exams can focus the efforts of both students and teachers.

I can quibble with details of the analyses presented in the paper. First, one of the analyses examines the effect of minimum competency exams on the probability that students obtain a general equivalency diploma (GED). For this analysis the authors grouped into the non-GED category both students who obtained a conventional high school diploma and students who dropped out of school and did not obtain a GED. Because a variety of studies show that GED recipients fare better in the labor market than dropouts without this credential, but they do not fare as well as conventional high school graduates, I do not know how to interpret the results of the analysis. ⁶⁸

Second, as the authors point out, the evidence on the effects of end-of-course exams comes from comparing outcomes for students who went to high school in New York state or North Carolina, which had end-of-course exams in the relevant year, with outcomes for students who attended high school in other states. It is not clear the extent to which differences in student outcomes stem from the end-of-course exams or from other respects in which North Carolina and New York differ from other states.

Besides these quibbles, I have two substantive issues to comment upon. First, are increased incentives for students and those who teach them a sufficient policy instrument for improving student outcomes? Incentives by themselves will solve problems that can be defined as individuals not doing things that they know how to do but are not motivated to do. When the external exams assess only low-level skills that can be mastered by more drill, then incentives for teachers and students to drill on basics will improve test scores. However, as states move toward examinations that assess higher-order skills and communication skills--skills that are increasingly important in an economy in which computers do a growing proportion of routine work--then drill alone will not do the job. Students need good instruction to learn to write well and to define and solve complex problems. Many teachers do not know how to help all students to master these skills. A small but growing body of research shows that professional development focused on helping teachers to teach more effectively the skills measured on demanding external assessments results in improved student test scores. In my view these focused professional development efforts are a necessary complement...