You may not know what a DBQ is. For most of my life, neither did I. But in the high schools of this region and the rest of the country it has become an important and in some ways fearsome term.

It haunts the dreams of 400,000 teenagers who will take the Advanced Placement exam in U.S. history Wednesday. It is part of a massive reform of the AP exam system that controls the schedules of most of the nation’s high schools every May.

DBQ is an acronym for “document-based question.” Multiple-choice questions make up 55 minutes of the 3-hour, 5-minute AP U.S. History exam, which has the second-largest number of AP test-takers, behind only the English Language and Composition exam. The rest of the time is devoted to two essay questions and the DBQ, an essay based on roughly 10 short historical documents or quotes. The DBQ counts more than any other question on the exam. It draws by far the most attention, including pre-exam guessing of what it will be about.

Is DBQ mania good for our schools? Philip W. Engle Jr., a history teacher at T.C. Williams High School in Alexandria, has been educating me on this. He has been an AP teacher for 20 years. He doesn’t think DBQs are bad. They “require students to work with documents and use higher-level thinking skills to use this information to defend a thesis,” Engle said. “This is a great skill to have, especially when writing research papers.”

But to Engle, the DBQ seems at odds with the view of the College Board — and most universities — that AP U.S. History is a college-level course.

The DBQ “is a unique writing task and one they will never do in college,” Engle said. “In my four years as a history major and in pursuing my master’s degree in history, never did I write a single DBQ essay. They are not college assignments.”

That may be changing. The Collegiate Learning Assessment, a key part of a movement to assess how much students learn in college, is essentially one long DBQ. Students receive letters, news clippings and government reports, then they are asked to do some real-world analysis, like telling a corporate board whether to buy a company plane.

John Williamson, a former Kentucky school district superintendent who is executive director for AP curriculum and content development, said Engle is correct that college professors don’t assign DBQs, but they seem to be requiring something similar. He did a search of college U.S. history course syllabi and found that in most cases, “students were asked to read multiple primary sources and then develop a thesis or respond to a question that required the synthesis of several primary sources.”

Engle has no problem with the growth of DBQs. But like many AP teachers, he thinks the mystery surrounding what will be on the DBQ and the rest of the history exam hurts learning.

“The AP test can ask anything from economic trends, political history, military history, religions, social and cultural history,” Engle said. Many teachers try to cover everything and have little time to assign research papers that develop students’ analytical skills.

Trevor Packer, College Board senior vice president for AP and college readiness, said he shares Engle’s breadth of content concerns. As part of a gradual reform of all AP subjects, Packer said, teachers preparing for the redesigned U.S. History course and exam, scheduled to take effect in fall 2014, will be given “much greater clarity and specificity” about what to cover.

AP history director Lawrence Charap said key documents and specific topics have been identified. Teachers will have more time to go deep into favorite issues. Long research papers, a rarity in U.S. schools, might even be possible. Students must still face the DBQ, but they should be better prepared and less afraid.