The "Center for Michigan" group has released a study showing that not all Michigan school districts are meeting the federally suggested 180-day school year. Underlying the length of the school year debate is the assumption that more time in school increases student achievement. Unfortunately, it doesn't.

When making international comparisons, advocates of longer school years often compare the United States with Japan and Korea, which outscore us on international tests and also have much longer school years. However, this comparison ignores the fact that schools differ in how they use their allocated time, so the number of days on a school calendar does not indicate how much time is devoted to actual academic instruction.

Comparing the number of instructional hours between countries is revealing. For example, the U.S. averaged just six fewer instructional hours per year than Korea, and actually provides four more hours than Japan, according to a 2003 Trends in International Mathematics and Science Study.

The summary of the 1999 TIMSS study underlines the conclusion that instructional time does correlate to higher tests scores:

"The amount of instructional time does not appear to be related to U.S. performance compared to other TIMSS nations. U.S. fourth graders spend more class time on mathematics and science than do their average  international counterparts. U.S. eighth graders spend more time in mathematics classes per year than students in Germany and Japan."

Why then, with similar numbers of instructional hours, do Japan and Korea consistently outscore the United States? There are a variety of reasons, but the the data does not support the conclusion that the longer school years and more hours of instruction are among them. Comparing the lengths of school years in different states or just among different Michigan school districts yields the same result: longer school years do not correlate with higher test scores.

Would-be reformers will have to look elsewhere for genuine solutions to the mediocre performance of Michigan public schools.

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