Size Matters, or Does it? - Amid budget crisis, parents and teachers fight for small classes. Some studies dissent.
 

Here are some key studies that are often cited about the merits of reducing class sizes:

 
• CSR Research Consortium: A four-year study of California's program found that it is hard to prove if smaller class sizes were the most likely cause of overall hikes in test scores in elementary grades. Other factors, like teacher quality, could have affected the achievement more. www.classize.org/

 
• Public Policy Institute of California: A study of six of California's largest districts found that the class-size-reduction program affected classes differently. In five districts, most schools saw test score increases. But in Los Angeles Unified, mostly low-income students had slightly lower test scores after class sizes were lowered. www.ppic.org/

 
• Vital Research: Los Angeles Unified hired this firm to study class-size reduction, finding larger test-score gains among third graders. The researchers did not review scores of English learners. www.vitalresearch.com

 
• WestEd studies: The nonprofit research, development and service agency group looked at results of several reports and studies. www.wested.org/cs/wew/view/top/5

 
• Tennessee's Project Star report: A four-year study found test-score gains among younger grades of students in smaller classes. But the classes were smaller than California's, and the state has few English learners. www.cde.ca.gov/classsize/eval/projstar.htm