Almost every industrial nation requires students to take subject-matter examinations created at the regional or national level, but many American educators strongly oppose the idea. "You can't fatten up cattle by weighing them. You have to feed them," is a typical U.S. response. Who is right? Do externally administered exams help raise achievement or are they another example of a quick fix?

Cornell University economist John Bishop helps answer this question in a monograph, "The Impact of Curriculum-Based Examinations on Learning in Canadian Secondary Schools." In an earlier paper, Bishop argued that "American students, parents, teachers, administrators and school boards apparently place a lower priority on the goal of academic achievement than their counterparts in Europe and East Asia." The reason, Bishop says, is that our system does not send signals that encourage effort and learning in high school, and it does not reward effort and learning. In "most other advanced countries," there are external exams that show how much students have learned:

Grades on these exams signal the student's achievement to colleges and employers and influence the jobs that graduates get and the universities and programs to which they are admitted .... In the United States, by contrast, students take aptitude tests that are not intended to assess the learning that has occurred in most of the classes taken in high school. The primary signals of academic achievement are grades and rank in class--criteria which assess achievement relative to other students in the school or classroom, not relative to an external standard.

What's wrong with the American way of doing it? When students are assessed relative to their "fellow students (using measures like grades and class rank) rather than relative to an absolute standard, students have a personal interest in persuading each other not to study." Everyone has an easier time if no one studies--and the same number get good grades. So students are pressured to do as little work as possible. Also, when there are no external standards, teachers are under pressure to lower their own standards so that more students look as though they're doing well. Bishop cites a study by New York State United Teachers in which 58 percent of the teacher leaders responded "Yes" to the question, "Is there pressure on your teachers to pass students who don't earn a passing grade?" Under a system of external exams, teachers and administrators can't do this. They have no choice but to help their students pass the exam, and their students are more likely to be interested in getting help.

The evidence Bishop cites to prove that externally administered, curriculum-based exams have a positive correlation with student achievement is impressive. First, there is the poor achievement of U.S. students in international comparisons with students from other countries, but this could stem from cultural differences. To avoid this problem, Bishop concentrates on studies that hold culture constant.

One of his examples is Sweden, which abandoned curriculum-based external exams in the 1970s. Between the First International Mathematics Study in 1964 and its replication in 1982, the percentage of students taking tough math and science courses declined substantially. This is bad news in itself. But you'd think it would result in higher scores for the more selective group that still took the courses. That's not what happened: "This more selected group of students scored slightly higher in algebra and lower in geometry on the anchor items that appeared in both assessments. Finns, by contrast, simultaneously increased the proportion of the age cohort taking college prep mathematics from 7 to 15 percent and significantly improved their mean scores."

In the U.S., the only state with external, curriculum-based exams is New York with its Regents. The Regents are not high-stakes exams--they do not determine grades, are not necessary for college admission and are generally ignored by employers. Nevertheless, they do have an effect on raising achievement levels: "When the family income, parental education, race and gender of SAT test takers are controlled, New York State has the highest adjusted mean Scholastic Aptitude Test score of the sample of 38 states with adequate numbers of test takers to be included in the study."

In Canada, some provinces have external exams while others do not, and Bishop finds a difference in student achievement between the two that extends all the way down into middle school. When these students graduated from high school, Bishop found, Students from Canadian provinces with examination systems were substantially (23 percent of a standard deviation) better prepared in mathematics and 18 percent of a standard deviation better prepared in science than students from provinces lacking such exams. The effect of an exam system on mathematics achievement of 13-year-olds is larger in a standard deviation metric than the decline in math SAT scores between 1969 and 1980 that has been such a focus of public concern.

External national or regional exams make a big difference. Weighing the cattle may not make them fatter, but the cattle are more likely to be well fed if the seller knows that the buyer is going to weigh them.