Many of the judges at the March 15 science fair were miles away, evaluating the students' presentations through photographs and other materials posted online.

The usual suspects were all on display: experiments involving yeast, anti-bacterial soaps, and herbicides; colorful cardboard posters; and nervous but knowledgeable student scientists explaining their work.

Yet two things made the March 15 presentation by the California Virtual Academies different from a traditional science fair. The first was its location, tucked into the children’s section of the Barnes & Noble bookstore in Corte Madera Town Center.

The second was the fact that many of the judges at the March 15 science fair were miles away, evaluating the students’ posters and presentations through photographs and other materials posted online.

“There are three judges for each presentation: a teacher, a parent, and a virtual judge,” said teacher Maya Creedman, who took part in the science fair. “Each presentation is photographed from a number of different angles so that it can be judged online.”

California Virtual Academies is an online charter school, based in the Southern California city of Simi Valley. Its K-8 students spend part of each day meeting with a credentialed teacher in an online classroom. The rest of their school day is spent working on projects, either alone or with the help of a parent.

“The child’s parent usually ends up taking on the traditional role of a teacher, while the teacher acts as more of a coach, working with the parent and student,” Creedman said. “We’re a public charter school, so our students have to take the California STAR tests, just as any other students do. And we use a curriculum that is very academically rigorous.”

That curriculum, developed by the for-profit Virginia company K12 Inc., is in use at several virtual schools throughout the nation.

“My sons had previously been enrolled in K12 schools in Connecticut and New York City,” said Michael Darigo, whose family recently moved to Mill Valley, Calif., from New York. “So they were familiar with the program. We like it because it allows them to learn at their own pace, to accelerate when they’re ready to move forward.”

The program has been popular with athletes on a rigorous training schedule, gifted students who appreciate an accelerated pace, and some special-needs students, who respond to the individual attention provided by the virtual teacher.

“There are a lot of students who have had behavior problems in a traditional brick-and-mortar school, who find it much easier to learn” at the virtual school, said Elizabeth Pasquale, who spent 13 years teaching in Larkspur’s Hall Middle School before becoming a special-education administrator for the California Virtual Academies. “They feel more motivated.”

The school regularly holds outings and activities, like the March 15 science fair, to give its students the opportunity to interact face to face, Creedman said. Those who do well in regional science fairs have the opportunity to compete at the state level.