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The pushback on class size limits

The DMN continues its commendable work on the upcoming legislative fight over class size limits by writing about the skeptics of smaller class sizes.

The most comprehensive assessment dates back just as far as the Texas law, to a four-year study that tracked more than 7,000 Tennessee students from kindergarten through third grade. The study found classes with 13 to 17 students performed better than classes with 22 to 25 students, even when the larger classes had a teacher’s aide. A follow-up showed students from the smaller classes succeeding more later in life.

Educators began proclaiming ideal class sizes in the teens. But Eric Hanushek, a senior fellow at Stanford University’s Hoover Institution and chairman of the Executive Committee for the Texas Schools Project, doubts the numbers.

“If you ask people in school, the optimum is always five fewer than we have today,” he said, adding that research shows little effect on classes that range from 15 to 30 students. “Part of the reason is because with a change of one or two students in a class, what you see is teachers doing exactly what they did before.”

Hanushek said class-size reduction has turned into a trend, one districts should re-examine. “Class-size reduction is the most expensive kind of reform,” he said.

Subsequent studies in California and Florida produced mixed findings, none with a magic number. A 1999 Texas Education Agency report linked academic benefits with classes under 20 students. It said research remained too preliminary to show any advantages to altering classes by one or two students.

“Roughly speaking, the difference between ineffective and effective classes is the equivalent of 10 to 13 students,” said Dan Goldhaber, director of the Center for Education Data and Research at the University of Washington-Bothell.


Goldhaber, the University of Washington researcher, said that small classes do offer benefits but that teacher quality is a more significant determiner of success.

“One size fits all is a pretty blunt instrument,” he said.

A few points:

1. The Hoover Institution is a right-wing think tank, and should have been identified in the story as such. Quoting them is like quoting someone from Heritage or Cato or some other place with an ideological mission. That doesn’t mean their data is invalid, just that it comes with a pre-defined perspective, and you should be aware of it when you evaluate its data.

2. What’s most striking about this is that nobody actually disputes the notion that smaller classes are beneficial. The arguments they advance are that you have to make class sizes a lot smaller to get real benefits, and that this is an expensive way to improve outcomes. To the former point, I refer you back to Leonie Haimsen, who provides more information here. To the latter, I take this as an admission that when someone claims we can’t solve education issues by throwing more money at them they are at best being ignorant. Certainly, one must weigh the cost of the benefit, and one must decide at what point the marginal benefit isn’t worth the increased cost. The flipside of that is that one must also weigh the loss of benefit one gets when seeking to cut costs. I don’t see any Republicans talking about what the contingency plan is if getting rid of the 22:1 ratio leads to a drop in student performance.

3. “Teacher quality” is the new buzz phrase that we are hearing from those who want to justify squeezing school budgets. Nobody disputes that having better teachers would be beneficial. However, the only objective method we really have right now for measuring teacher quality is standardized test scores, which are also blunt instruments. I am not aware of any plans or proposals to hire and retain better teachers beyond the Teach for America grants that may be subject to the same budget pressures as everything else and whose critics make the same “insufficient bang for the buck” claim that class size skeptics do. Another virtue of class size limits is that it’s easy to implement and to know that’s you’ve done it; if there’s a way to know that you’re hiring better teachers, it’s not getting much discussion. Finally, how much would it cost to improve outcomes by improving teacher quality, and would this be attainable in the current budget environment? Again, I have not seen any discussion of that.

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  2. Rob D'Amico says:

    Thanks for your coverage of this. You can find continuing coverage and commentary at