At the Early Head Start center in Manassas, teachers take care that each toy and picture book is age-appropriate, the cots at nap time are placed 36 inches apart and every activity, including diaper-changing, is a time for learning.

“Look, your favorite color,” said one teacher pointing to the illustrated waistband of a toddler’s diaper. She kept the changing-
table conversation going, then helped the little girl wash her hands and counted the steps down from the sink “1, 2,” completing mini-lessons in vocabulary, hygiene and numeracy.

These are the kinds of things that investigators looked at when they evaluated the center in the predominantly low-income Georgetown South neighborhood this year and gave it five stars, making it the only preschool in Virginia to earn the top mark in a voluntary rating system that is being rolled out across the state.

The Virginia Star Quality Initiative is aimed at assessing and improving quality in early-childhood programs and helping parents make more-informed choices about where they leave their children for eight hours or more a day. Dozens of states, including Maryland as well as the District, have developed similar systems.

Limited government funding has largely been focused on making preschool affordable and accessible so that parents can work, not on providing the best learning environment, said W. Steven Barnett, director of the National Institute for Early Education Research at Rutgers University.

The baseline is finding a program that “will keep your child safe and healthy,” he said. “Most parents are happy if they find that.”

But there is growing recognition that the years before kindergarten are a critical time for learning. Research has shown that quality preschool programs offer long-term benefits, including better school performance and graduation rates and higher rates of employment and home ownership. The potential payoff is greatest for children in low-earning households and those who have less stability and stimulation at home.

President Obama has proposed expanding preschool and tying extra funding to high-quality programs.

Virginia’s system, which was launched in 2007, has not yet been rolled out statewide. About 350 child-care centers have ratings, a small number compared with the nearly 6,000 child day-care providers that are listed on the Virginia Department of Social Services Web site.

Participants receive mentoring and on-site training before and after they are evaluated and can qualify for grants to support professional development and to purchase toys and materials to help them meet improvement goals.

The initiative also promotes morale among teachers and directors in a little-recognized field.

“I was screaming when I found out” about the five stars awarded, said Isha Barrie, director of the Early Head Start program at Georgetown South. “I couldn’t believe it.”

The rating system evaluates centers according to four standards: the education and training of the early-childhood educators, how skillfully they interact with their students, staffing ratios and group size, and the overall physical learning environment and instructional practices.

The most difficult standard for centers to meet is the first one, experts say. Top marks are reserved for settings where directors have a master’s degree, 75 percent of teachers have a bachelor of science or arts degree or higher in a child-related field, and 75 percent of assistant teachers have a community-college certificate in a subject area related to childhood education.

In a field where annual salaries can dip below $20,000, it’s very hard to recruit and retain a well-educated workforce.

The most heavily weighted category, and many say the hardest to rate, is how teachers interact with students. Evaluators are trained to use a tool developed at the University of Virginia to measure how effectively teachers create a positive environment or implement classroom routines, or how well they work with children to expand their thinking and problem-solving skills.

This was an area where the Georgetown South program excelled, according to Morgan Janke, director of quality improvement for the Virginia Early Childhood Foundation, which administers the system in partnership with the state and other local groups dedicated to improving education.

Head Start programs have the advantage of an added layer of standards, federal funding and complementary social services, though the quality and impact of these programs has come under scrutiny.

On a July morning, Pat Victorson, an early-childhood educator who mentors other teachers as part of the quality initiative in Prince William County, highlighted some things that Georgetown South was doing well.

She noticed how carefully teachers set up activity stations, so the 2-year-olds flowed seamlessly from a game of dressing up in firefighter and police uniforms to rolling out green Play-Doh at a table across the room.

She noted the encouragement that a teacher gave to a student who showed off his Play-Doh creation. And on the playground, she found enough toys and equipment to develop at least “seven to nine motor skills.” In another area, teachers had laid out books on a blanket where children were happily reading.

“This is what we would love to see for all children,” Victorson said.