The fifty-minute periods were organized in a consistent, predictable structure (an important element of learning, Reisman maintains), with the teacher typically devoting ten minutes to introducing or reinforcing background information through lecturing, use of video, or textbook questions followed by thirty minutes of document work, individually or in groups. The background presentation was designed to prepare students for the documents to come, and often to set up “straw men” that the documents could challenge. The document work was organized around an essential question (for example, “Why did the Homestead strike of 1892 turn violent?”), and included documents offering conflicting interpretations. Questions in the handouts were designed to direct student attention toward interrogation of the validity of the documents. The final ten minutes were taken up with whole-class discussion, during which, Reisman hoped, students would engage in historical argument, making claims supported by specific evidence from the background material and documents.