A study published by the American Educational Research Association found that significantly smaller class sizes, from 13 to 17 students, at an early age--kindergarten or first grade--led to statistically significant benefits for the children involved. Both reading and math skills ranked higher than for those in a standard-size class of 22 to 26 students. These results were not noted when classes were reduced by only a few students, such as lowering class size from 25 to 21. According to research compiled by Edith Helmich and Leighton Wasem, for the Illinois State Board of Education, class sizes need to be below 20 to show any significant benefits to reduced load.
Research in Wisconsin, called the SAGE project, showed that students who live in poverty and students who are part of ethnic minority groups benefit the most from small class sizes early in their academic careers. Being members of smaller-sized classes reduces the achievement gap between these students and majority Caucasian, middle-class students. It also leads to fewer disciplinary problems, more students going on to college and a decreased number of students who are retained in a grade, unable to pass to the next grade.
Small class sizes are believed to lead to changes in student and teacher behavior. In smaller classes, students have more pressure to participate in all learning activities and are less easily overlooked. The teachers are able to pay more attention to individual students. Disruptive behavior is more quickly stifled, and students tend to give more attention to learning activities. An aide in the classroom does not show the same results, however. Adding a full-time aide to the classroom did not significantly increase math and reading marks in the American Education Research Association-published study.
Even if a school district sees some savings from smaller class sizes because it has a lower dropout rate and fewer students being held back to repeat a grade, there will be increased costs if the district reduces class sizes. Hiring new staff is expensive. One solution is to reassign specialty teachers who have done "pullout" activities such as Title I, special education and remedial classes to full-time classroom duty. These pullout programs are expensive and the data does not show that they are effective at increasing student achievement or decreasing dropout rates, according to educational researcher E.A. Hanushek.