Children enrolled in Los Angeles Universal Preschool programs made significant improvements in the social and emotional skills needed to do well in kindergarten, according to a study released Monday. The gains were especially pronounced for English language learners, the study showed.

The findings confirmed observations of preschool teachers that children attending high-quality programs are better prepared for kindergarten. For the first time, the study provided data to back up those observations, officials with the nonprofit preschool organization said.

"This is unique because there's very little research in terms of cognitive progression in the preschool years," said Celia C. Ayala, chief operating officer for Los Angeles Universal Preschool. "We know there are differences, we see the differences, but this gives us a way to assess improvements."

The Los Angeles Universal Preschool is an independent organization funded primarily by a voter-approved tobacco tax and launched in 2005 to provide preschool to 4-year-olds in Los Angeles County. It serves about 10,000 children in 325 preschools.

The study, commissioned by the organization and conducted by the San-Jose-based Applied Survey Research, measured the readiness skills of 437 children at 24 preschools in the fall of 2008 and reassessed 364 of those children in sping 2009.

Skills that were assessed included proficiency in using crayons, washing hands, controlling impulses, expressing needs, counting to 10 and recognizing letters of the alphabet as well as shapes and colors.

The study found that the percentage of children scoring near proficient on all behaviors increased from 22% in the fall to 72% in the spring. English learners who scored significantly lower than their non-English learner peers in fall 2008 had closed the gap in most measures by the spring. In general