About a hundred of these schools dot the county's countryside, said Kim Fortney, vice president of the Lancaster Cultural History Museum. Each school has about 25 to 30 first- through eighth-graders.
A 1972 U.S. Supreme Court decision exempts Amish children from having to attend school beyond eighth grade for religious reasons.
The Amish's communal society takes a practical view of education. That is, "too much education might make you proud" and undermine the community, said Peter Siebert, director of the Lancaster Heritage Center, which includes the museum.
Boys and girls travel up to 10 miles to school on foot or by bicycle or scooter. They study reading, writing, English, math, geography, history, German, music, art and the Bible.
Book learning provides half the knowledge that the Amish believe children need. Hands-on learning to develop their farming and homemaking skills rounds out their education.
Textbooks used in Amish schools are sometimes similar to those found in public schools, although there are also texts written by Amish for Amish and printed in an Amish-owned print shop in the county, Fortney said.
Teachers tend to be younger, unmarried women who have only hours of training before they go into classrooms, said Robert McGowan, a retired California school administrator who is a friend of Pennsylvania's Amish community.
They are paid through a tax collected from families with school-age children and administered by a community school board.
Aides might be employed for large classes, McGowan said. Parents also help in the classrooms.
Amish schoolhouses' amenities are meager compared with those of public schools. There's no electricity. Classrooms consist primarily of blackboards, desks and chairs. Some schools are heated by wood or coal stoves, McGowan said. The restrooms are outhouses. Recreational facilities consist of swing sets and baseball diamonds.
State Education Department records on the West Nickel Mines Amish School, where Monday's shootings occurred, provide little insight into the school's operation.
It was certified in 1985, "but there's no way for us to know they didn't exist before that," said department spokesman Mike Storm.
To receive certification, Amish schools provide basic information and attest that school includes at least 100 days of instruction.
"They are the least-regulated form of school," Storm said. "That's been the tradition of state law, to respect their privacy."