Educators violated the rules by photocopying the previous year's test, providing students with questions beforehand, handing back answers to correct or providing dictionaries and other resource materials, the Toronto Mail and Globe reported Tuesday.
Marie Parsons, chief assessment officer at Ontario's Education Quality and Accountability Office in Toronto, said some educators cheated and some inadvertently violated the rules.
"Unfortunately, schools are a microcosm of the real world. We've got people and educational personnel who, for whatever reason, decide they're going to do something that isn't according to what is allowed, and we get these problems," said Todd Rogers, an education professor at the University of Alberta.
Many teachers say they are under great pressure to improve test scores, forcing them to abandon other elements of a balanced curriculum.
"When we end up measuring who is good at doing tests, then you're going to have problems with cheating," Doug Jolliffe, president of the Ontario Secondary School Teacher's Federation's Toronto chapter, said.
"Teachers are teaching to the test in order to bring about the result the government wants," said New Democrat Party education critic Rosario Marchese.