Skipping classes, particularly big lectures where an absence is likely to go undetected, is a tradition among college undergraduates. These days, however, some professors say they're seeing more  _ , as students make the most of new technologies as learning aids. Americ Azevedo taught an "Introduction to Computers" at the University of California, Berkeley, US last semester. By visiting the course's website, the 200 enrolled students could download audio recordings or watch digital videos of the lectures, as well as read the instructor's detailed lecture notes. But there was one big problem: So many of the undergraduates relied on the technology that at times only 20 or so actually showed up for class. Doug Suda, 19, a student in Azevedo's class last semester, said he skipped about three-quarter of the lectures. It's largely because he was busy with an off-campus job and was taking the course to fulfill a business major requirement. At the end of the term, Suda prepared hurriedly for the final exam by watching videos of about 15 lectures over three days. "If I hadn't that... I would probably fail the class," said Suda, who instead received a B-plus. Despite the concerns about absenteeism, schools are increasingly experimenting with ways to let students watch or listen to lectures on their computers or digital music players, like iPods. Last month, Harvard Medical School began "Podcasting" lectures. Students can download them into digital musical players, and study while they, say, go for a walk. As many academics accept the electronic innovation, others are pushing back. To encourage attendance, they are applying low-tech tactics, like giving more surprising quizzes or cutting back their online offerings. Lee Chanian, a UCLA economics professor, says "too much technology leads to passive learning environment and encourage more absenteeism". He now puts fewer lecture materials online, and provides extensive notes only for the most complicated topics. According to the passage, to encourage attendance, some academics are applying the following lower-tech ways EXCEPT  _  .
giving more surprise quizzes cutting off their online offerings providing extensive notes only for the most complicated topics putting fewer lecture materials online