LINCOLN, Neb. (AP) - For high school senior Sarah Dicke, getting to psychology class means walking up the stairs of her home, sitting down at her parents' computer and dialing up the Internet.
Her textbook is online, as are homework assignments, quiz questions and tests.
Dicke, who attends Lincoln High School, is among the growing number of students turning to the Internet to complete courses required for graduation or to get a jump start on college.
When it's convenient, she logs on, does her homework and e-mails it across town to a teacher who evaluates it and replies with her grade. Dicke doesn't feel rushed because she has a full calendar year to complete the course.
"Nobody calls me and reminds me to do it," she says while navigating the Web site where her assignments are posted.
Fifteen percent of U.S. high schools offer access to online classes, according to a survey by Market Data Retrieval, an education research group in Shelton, Conn.
At least 16 Web sites offer classes good toward high school diplomas or college credit. Site operators include Florida's state department of education, several universities, charter schools and private corporations.
"What we're trying to do is help the schools with alternatives and options," said Jim Schiefelbein, principal of the University of Nebraska's Independent Study High School, which offers classes through the Web site class.com.
Supporters of online teaching see it as the next frontier of education, bringing the class to the students rather than the other way around.
"I don't really see any drawbacks," Schiefelbein said. "It's just different."
Class.com, which began last year, offers dozens of courses that are available to students in 600-plus high schools in all 50 states and 135 countries.
Dicke is taking psychology through class.com, which charges up to $295 per course. Her tab is being picked up by Lincoln High, which offers students online classes free of charge.
Online instruction also provides solutions to school districts with limited resources.
In Stanton, Ky., student Alan Tipton took Spanish via the Internet last spring.
His high school, Powell County, couldn't offer the class because a statewide teacher shortage had stymied its efforts to hire a Spanish teacher.
So Tipton took the class through Kentucky's Virtual High School, which began offering classes in January. Powell County High set up a room and a computer where he could take the class during regular school hours.
"It was a completely different environment," said Tipton, now a freshman at Vanderbilt University in Nashville, Tenn. "It was mostly self-motivating. All of the work, you had to do on your own."
Online learning is not for everyone. Even its most ardent advocates say the open-ended, freestyle form of instruction can be difficult for students who need more structure.
Class sizes vary from a handful to more than 20. Often students interact in chat rooms with others taking the same class, though discussions of course material can be difficult because students work at their own pace.
Those who offer Internet-based high school courses say enrollment is increasing.
Kentucky's Virtual High School opened in January with 47 students. This fall, 300 signed up for classes to supplement what they are learning in their regular schools.
Director Linda Pittenger said online learning is not just for the advanced learner.
"It's powerful and can be very effective with students who are academically at-risk," she said.
Who teaches the courses varies depending on the policy of the Web site.
Nebraska-based class.com has a staff of 13 teachers for students enrolled through the Independent Study High School. Kentucky's Virtual High School contracts with educators in Kentucky, some of them retired teachers who want to teach but don't want to deal with tedious tasks like lunchroom duty.
Online learning is still in its infancy, and a lot more needs to be learned about it, said Michael Carr, with the National Association of Secondary School Principals.
Virtual high schools must address issues like cheating, arranging for tutors and ensuring access to adequate computers, he said.
"There's great potential there, but in education we've come up with all kinds of panaceas," he said. "Technology is a tool, it's not the only answer."