Mitt Romney was on the defensive today at an education roundtable in Philadelphia, trying to tell teachers that smaller class sizes are less important than “school choice:” Romney Defends Class Size Stance to Teachers.

(CNN) - Mitt Romney, who is spending this week promoting a plan for America’s public school system, spent Thursday morning defending his stance that smaller class sizes don’t necessarily equate with better learning in schools.

Romney participated in an education roundtable at a charter school in Philadelphia the day after laying out his education plan to Latino small business owners in Washington. Romney’s plan emphasizes school choice over other factors, including efforts to reduce the number of students in classrooms.

Speaking of his time as governor of Massachusetts, Romney said he was frequently told that smaller class sizes would lead to better learning, but that certain studies advised otherwise.

“I came into office and talked to people and said, ‘What can we do to improve our schools?’” Romney said at his Thursday event. “And a number of folks said we need smaller classroom sizes, that will make the biggest difference.”

Romney went on to cite a study that showed no correlation between classroom size and performance, naming schools in Cambridge, Massachusetts as an example.

This is such a common right wing tactic that whenever someone like Romney cites a “study” to support a claim that seems counter-intuitive, you should always double-check to see what credible sources say about the matter. In this case, the fact is that the majority of credible studies show that smaller class sizes absolutely are an important factor in better education results: Education Week Research Center: Class Size:

Research, for the most part, tends to support the belief in the benefits of small classes. While not all studies on the subject have shown that students learn more in smaller settings—and some are still ongoing—most have linked smaller classes to improvements in achievement.

The biggest and most credible of those studies, Tennessee’s statewide Student/Teacher Achievement Ratio, or STAR, project, begun in the late 1970s, found that the learning gains students made in classes of 13 to 17 students persisted long after the students moved back into average-size classes (HEROS, 2011). What’s more, the Tennessee researchers found, poor and African-American students appeared to reap the greatest learning gains in smaller classes. After kindergarten, the gains black students made in smaller classes were typically twice as large as those for whites. Follow-up studies through the years have found the students who had been in small classes in their early years had better academic and personal outcomes throughout their school years and beyond (Krueger, 2001; Sparks, 2011).

Likewise, a 2001 evaluation of the Student Achievement Guarantee in Education, or SAGE, class size reduction program by researchers at the University of Wisconsin-Milwaukee found that a five-year-old program of class-size reduction in Wisconsin resulted in higher achievement for children living in poverty. Research from Columbia University Teachers College in New York showed the context of class-size reduction can affect its success in improving student achievement (Ready, 2008). Similarly, Charles M. Achilles, one of the original principal researchers on the STAR study, has said researchers and policymakers will have difficulty replicating the improvements seen in the STAR study without including key elements of that program, such as early intervention and small class sizes of three years or more (Achilles, 2008).

The teachers at Romney’s roundtable meeting were clearly rather aghast at his claims:

“I can’t think of any teacher in the whole time I’ve been teaching, for 10 years, 13 years, who would say that more students would benefit them,” Steven Morris, the teacher, said. “And I can’t think of a parent who would say ‘I would like my student to be in a classroom with a lot of kids with only one teacher.’ So I’m kind of wondering where this research comes from.”

Another teacher participating in the roundtable said unequivocally that he had too many students in his classroom.

“It’s too large,” the second teacher said. “It varies between classes, anywhere between 20 and 28. You can give more personalized attention to each student if you have a smaller class size.”

Why is Romney emphasizing “school choice” over class size, even though most studies disagree with his approach? The most likely answer is that he’s pandering to the religious right again, where “school choice” is a culture warrior code word for religion-based home schooling.