Mixed age groups lead to a halting start.

• Position: Head Start - Brief article

Most Head Start classrooms serve children of mixed ages and that hurts the academic growth of the older kids, a national study suggests. Researchers found that four-year-olds In Head Start classrooms that included higher concentrations of three-year-olds were up to five months behind in academic development compared with their peers In classrooms with fewer younger children.

That is a problem because about 75% of all Head Start classrooms are mixed age. Head Start is a Federal preschool program that promotes the school readiness of children In low-income families from ages three to five.

"While there has been some enthusiasm for mixed-age classrooms, our results suggest there may be a significant downside for older children," says Kelly Purtell, coauthor of the study and assistant professor of human sciences at Ohio State University, Columbus. "Four-year-olds are often enrolled in classrooms that are less supportive of their academic learning."

The results also may help explain why a national evaluation of the Head Start program found that it only was modestly effective In helping the academic achievement of...