About 10 Corona del Mar High School sophomores had test answers before an exam earlier this school year by buying test banks on Amazon.com, the school's principal said at Wednesday's PTA meeting.

Test banks provide chapter-by-chapter questions for tests, which textbook publishers provide to ensure teachers craft exams that properly assess student learning, Principal Tim Bryan said.

"If you have the test questions in advance, you're cheating," he said. "They altered the conditions of the test. It's a really big issue for us."

The history teacher discovered the cheating when someone, likely a student, wrote an anonymous note, Bryan said.

In all, 180 students took the test in question.

Bryan said he did not know if the teacher planned to have students retake the test, or if the test scores would be discarded — all scenarios that would hurt students who studied and honestly earned good grades. He also declined to discuss whether students involved would be disciplined.

Some students and parents may have thought that the test banks were legitimate study guides, he said, not realizing that test banks are usually fiercely protected by publishers and available only when buying sets of textbooks, or to teachers who have teacher identification numbers.

But parents at the meeting said that the word among students was that those involved knew they had illicit information, and some were offering the information for sale to other students. One parents said her daughter asked her to buy the test bank, but she declined and said it looked like cheating — not knowing that other parents and students were buying the information.

A district official called the publishing company, Bryan said, and the test bank in question is no longer available on Amazon.

A parent whose daughter is taking the history class but who did not have test bank information said she heard about the cheating over the winter break.

"She's frustrated, and I'm very frustrated," said the parent, who asked her name not be used to protect her daughter's privacy. "When you have a child who is taking a very difficult class, being challenged and doing well, and then find out that other kids are working the system — it's bad. It's a program fail."

The parent said the teacher and administrators were handling a bad situation well, discussing it in class and working on ways to make sure students know that cheating is not permissible.

"They were on it the minute they heard about it," the parent said.

Bryan said CdM High and this particular class are unlikely unique, and that cheating is a problem throughout the nation.

Students and teachers work together continually to combat cheating, which has included complicated maneuvers such as steaming off the labels of water bottles, writing notes and then reattaching them so that the answers are visible through the clear liquid. Water bottles aren't permitted on desk during tests now, he said.

Students sometimes feel pressure to cheat because they want to get good grades to satisfy parents or to get into college, according to research by the school's National Honor Society.

Some parents Wednesday suggested that the school conduct an all-grades assembly about cheating, and that a letter be sent to parents discussing this event.

"We're going to have to take a look at all this," Bryan said. "But this is not a CdM-specific problem. It's getting harder and harder and harder for our kids to navigate their moral compass. There's a lot of pressure."

Twitter: @coronadelmartdy