Do you have evidence that class size doesn't matter? It seems intuitively obvious that class size does matter. Consider a single teacher teaching 60,000 average students in a stadium sized classroom versus a single teacher in a classroom with 20 average students. It seems to me that the probability of success in the latter classroom would be significantly higher than in the former. I don't know this to be true but it seems like it should be true. I'd be interested in knowing if there is research supporting your position.

He can't really provide the evidence because it does not exist in any meaningful manner. There is an overwhelming amount of data showing that reduced class sizes lead to better overall student performance and that smaller classes have a disproportionately large effect when used in disadvantaged/urban schools and when used very early (e.g. K-2nd grade.)

If the data is overwhelming, how come you don't cite any of it?

The first few google results that address this point [1] seem to disagree with your claim that the data is overwhelming.

At the college level at least, student performance is unaffected by class size: http://sigmaa.maa.org/rume/crume2010/Archive/Gleason.pdf

In french grades 1-2, teacher education and class size (variation of 10 students) affects outcomes by only 3%, which they claim is statistically significant: http://www.ilr.cornell.edu/international/events/upload/Prost...

But I'm no expert. If you have data, can you cite it? Because a quick google search suggests patrick is right and you are wrong.

[1] A few of the studies at the top of google results don't address student performance, but instead focus on student satisfaction.

Since "google it" seems to be the alpha and omega of your research abilities, here are some papers and research from the last five years that supports the case that smaller class sizes leads to better student outcomes when applied to K-6 education (as in long-term quantitative results and not just "student satisfaction"):

Spyros Konstantopoulos and Vicki Chun, What Are the Long-Term Effects of Small Classes on the Achievement Gap? Evidence from the Lasting Benefits Study, American Journal of Education 116, November 2009.

Peter Muennig and Steven H. Woolf, Health and Economic Benefits of Reducing the Number of Students per Classroom in US Primary Schools, American Journal of Public Health,  published online September 27, 2007. 

Philip Babcock and Julian R. Betts, Reduced-class Distinctions: Effort, Ability and the Education Production Function, NBER Working paper 14777, March 2009. 

Sarah Theule Lubienski et.al., Achievement Differences and School Type: The Role of School Climate, Teacher Certification, and Instruction, American Journal of Education 115, November 2008.

Elizabeth Graue, et.al. The Wisdom of Class-Size Reduction, American Educational Research Journal, September 2007, Vol. 44, No. 3. 

Douglas D. Ready and Valerie E. Lee, Optimal Context Size in Elementary Schools: Disentangling the Effects of Class Size and School Size, Brookings Papers on Education Policy, 2006/2007, pp. 99-135. 

Fatih Unlu, California Class Size Reduction Reform: New Findings from the NAEP, Princeton Univ., Nov. 2005

Jeremy D. Finn et.al., Small Classes in the Early Grades, Academic Achievement, and Graduating From High School,  Journal of Educational Psychology, 2005.

The best that the opponents of initiatives to reduce class sizes can muster are exemplified the recent efforts by anti-tax groups to fight Amendment 9 in Florida (see http://floridataxwatch.org/archive/amendment9.html for an example) where there is a a great deal of political weaseling to try to minimize the available data. No studies are presented that show that reduced class sizes have a detrimental effect and a lot of words are spent trying to spin the results that are available.

We are not talking about college-level instruction and you know that. The attempt to claim that research on college pedagogy is in any way applicable to elementary education is poor sophistry at best. To return the favor, how about you start listing some studies that show that reduced class sizes in K-6 have no long-terms effects on student outcome?

Look, I don't claim to be an expert. I was just asking you to cite some of the voluminous research you claimed existed, and pointing out that the case seems far from clear. I just cited the first two on-point google results, one of which was about grade 1. Also, no one is claiming reduced class sizes have a detrimental effect. The claim is that their effect is small and probably not cost effective.

Now, on to your citations. Your first paper (Konstantantopoulos and Chun) agrees with me. It shows an achievement gain is 0.04-0.1 standard deviations, decreasing with time (they don't even bother to look past grade 8). The increase in cost is 66% (reducing class size from 25 to 15).

Graduation probabilities are also increased by 3% (for students not receiving a free lunch) to 18% (for students receiving a free lunch), after 4 years of small class size (according to the Finn paper). So far, the only effect that seems significant is the graduation probability for students receiving a free lunch (assuming this particular effect is real, rather than just data mining).

(Note: several of your other studies don't even try to address the claim that lower class sizes improve student achievement. Your paper by Woolf and Muennig is just an advocacy piece, assuming that education is the cause of all good things and arguing that we need more of it. )

You cited a study of college-age students and a study from France when there is a wealth of domestic data ready for your to cite and you expect the claims to be taken seriously? As far as your claim that these were the first two on-point google results, I guess it just depends on what you search for:

http://lmgtfy.com/?q=research+class+size+student+achievement

I beleive that you are misreading the Konstantantopoulos and Chun if you think that it agrees with you. An achievement gain of that size in education is actually quite significant and both the abstract and text make this clear. To dismiss the fact that the study followed a third grade class for five years and showed improvement down the line by saying that "they don't even bother to look past grade 8" is more spin than reasoned analysis.

Once again, please provide the links to papers that show that smaller class sizes do not have a long-term positive impact on student performance. So far it seems you are much like the anti-CSR group I mentioned previously, all spin and bullshit. Prove me wrong.

Why the hostility? You picked a different search term than I did, big whoop (I picked "class size student outcome"). I guess that makes me a bullshit artist.

Now, you may be right that a 0.04-0.12 standard deviation improvement is large within the field of educational interventions. All that proves is that the entire field of educational interventions has produced little/no gains.

This is how small 0.12 standard deviations is: http://imgur.com/BJDHc

You and the authors can attempt to spin that as something significant, but it doesn't contradict Patrick's original assertion. He claimed that smaller classes "do little, if anything, for education." You cited a source showing that they do little. You didn't contradict him.

Here is my citation, which shows that smaller classes "do little, if anything, for education": Spyros Konstantopoulos and Vicki Chun, What Are the Long-Term Effects of Small Classes on the Achievement Gap? Evidence from the Lasting Benefits Study, American Journal of Education 116, November 2009.

"The most often cited research o this matter was conducted by Gene Glass and Mary Lee Smith. [...] Several features of the resulting curve stand out. First, for class sizes in the range of twenty to forty students, the effects are minimal. Second, significant improvement in student achievement does not occur until class sizes are in the range of fifteen students or below.[1]

[...]

The immense costs make classes smaller than 15 utterly out of the question. In 1986, for example, a reduction of the national average for regularly convened classes from 24 to 23 pupils would have required almost 73,000 more teachers and 5 billion additional dollars, not counting the expenses of building more classrooms. Reducing the average class to 20 students would require over 335,000 more teachers at an added $22.8 billion. At 15 students, 1 million extra classroom teachers would be needed and added costs close to $69 billion."

[1] Riordan notes that there were some problems with this study, but that despite these problems later research has validated the original curve.

source: Equality And Achievement by Cornelius Riordan, p. 164

It may be true in a political sense that having classes smaller than 15 students is out of the question but the cost isn't that great. We spend around $1.2 trillion in national defense. $70 billion more for education is not that great a sum.

At all levels of government (i.e., federal, state and local), we spend $850B on education and $792B on the military, your guess of $1.2 trillion is not even close.

http://www.usgovernmentspending.com/year2009_US.html

Reducing class sizes from 25 to 15 would require 66% more teachers, lets guestimate that the cost of education would rise by 40% [1]. That's $340B for fairly small improvements in educational outcomes (0.04-0.12 standard deviations, according to stats posted elsewhere in this thread).

[1] Not all costs would scale upward with teacher salaries. We could sometimes repurpose 2 30 student classrooms into 4 15 student classrooms, and some administrative costs would scale with # of students.

I guess you've never heard of supplemental spending, black operations and whatnot. Defense spending isn't solely the defense department. We spend a great deal of money on intelligence services.

My response was solely to the quoted number of $70 billion or so. $80 billion is not a lot. It appears the number quoted was in 1984 dollars or something like that. Even then it still isn't a lot given that the defense budget then was around $300 billion.

I prefer spending money on education, health, peaceful purposes but not everyone agrees. The point I made though, still stands. It's a not a lot of money and it isn't as if we couldn't do it.

That's for the 1986 student population with 1986 dollars. If you correct it for the estimated 2018 student population and 2010 dollars, you're already around $190 billion. And that's not counting the cost of building new schools, or factoring in the rise in per-student spending. You're easily looking at well over a trillion dollars when all is said and done.

Also, decreasing the class size to 15 students wouldn't get you very much improvement over current class sizes. It's only for every incremental decrease below 15 that you start to see meaningful improvement.

It’s not nearly as clear as you make it out to be. Of the randomized controlled trials that I know of [1], one study has shown that reducing class size from 25 to 15 has a large positive effect, but another has shown that reducing class size from 40 to 30 has no effect. Also, assigning a teacher’s aide, so that a class of 50 is taught by two people also has no effect. The problem is that such studies are expensive and hard to generalize. Is it really that going from 25 to 15 always has an effect and that going from 40 to 30 never does, or was there something about the particular circumstances of those trials that made class size matter in one case and not the other?

Another problem is that even if reducing class size is effective is that, in the short run, there’s a fixed supply of good teachers. This isn’t a problem when you’re running an RCT on a few schools, but if you want to initiate state-wide (or nation-wide) reform, it’s not clear that throwing a bunch of unqualified teachers into small classrooms will help.

[1]Hacsi’s Children as Pawns: The Politics of Educational Reform has a good summary of evidence to date, as of 2003

Patrick is focusing on class size variations typically encountered in the real world (typically 0-40). You are focusing on class size variation in a world populated by straw men (0-60,000).

I guess this is an implicit admission on your part that class size matters. Very good. I agree with you.

At most large universities freshman and sophomore classes can be found in the hundreds. (They typically come with recitation but these are usually glorified tutoring sessions.) At my college class sizes in the department of mathematics run at 45. Typical depends on what institution you are talking about.

Given that class size matters it becomes a relevant topic on what the optimal size is. He made the statement with regard to class size:

" They do little, if anything, for education."

This is clearly not the case.

The last time I looked into the empirical evidence on this in primary school, the finding was that class size makes a big difference if there are 13 or fewer students in a class because the teacher can use a style where he spends individual time with each student. But from 15 to 40 it flat lines because the teacher has to switch to lecture mode. So, unless you can reduce class size to 13, there's no benefit to doing it. And there really aren't any schools that are taking it that far. So they might as well ramp up to 40 students (above this discipline and control becomes a problem in K-12) and use the salary savings to buy textbooks or other materials, things that many school districts are now opting out of because their administrative, salary and other such costs are now so high.

Many countries that do better achievement wise than the US (assuming measured achievement results are valuable, which is debatable) have large classroom sizes in primary education. Japan's average is 40 students:

> The 1999 Pennsylvania State University study done by Suetling Pong concluded that the effect of class size on achievement is very small. It compared ten industrialized nations other than the U.S. and found that students in Australia, Flemish Belgium and France did significantly better in larger math classes. Class size had no effect on students in Canada, Germany, Iceland, South Korea and Singapore. And students in Japan, who consistently outscore U.S. students in math and science, frequently attend math classes of 40 or more students. source: http://www.edreform.com/Archive/?Debunking_the_Class_Size_My...

Not all teachers are created equal. Your pro small classes point applies if all teachers are just as good. However if one teacher teaches 60,000 people, you can pick the best teacher in the city. If one teacher teaches 20 then 20 students get the best teacher, and the other 59,980 dont. Instead of just hiring the top 1 teacher, you must now hire the top 3,000 teachers. The average skill of the top 3,000 will heavily affect the average level of teaching of the whole 60,000 students.

If you doubled all class sizes you might be able to double the quality of teaching.

In my day it was educational TV programs that were going to save us. For anybody old enough to remember Vax it was probably educational film strips.