 making it difficult for an agent to keep pace. "I may be calling someone for myself or on behalf of my boss, my wife, or my kids," says Linden. "The system would have to switch radically between different contexts." Linden notes that many university and corporate laboratories are working on agent research. "But it's going to be a long time before something useful comes out of that," he says. 5.5 TELE-LEARNING OPENS HORIZONS Tele-learning may actually be better than in-person instruction, since online classes can more easily expose students to new cultures and concepts, says an Ohio State University researcher. Courses taught on the Web allow students to interact with people from around the world and to learn new perspectives that they could never expe- rience in a typical classroom, says Merry Merryfield, professor of social studies and global education at Ohio State University. She notes that online classes also allow students to tackle more controversial subjects, ensure that all stu- dents participate equally, and offer the opportunity for more thoughtful and in-depth discussions. Merryfield teaches graduate-level online classes on global education to teachers in the United States and around the world. In a recent study, she examined the online interaction of 92 U.S. teachers who took her courses and 22 cultural consultants-educators from other countries that Merryfield hired to provide the American teachers with international perspectives. The results, she says, showed the value of online classes in global education. "Online tech- nologies provide opportunities for teachers to experience a more global com- A NEW APPROACH TO VIRUS SCANNING munity than is possible face-to-face," says Merryfield. "In a course I taught last summer, I had 65 people from 18 states and 12 countries. This diversity affected the course and the content in many ways and greatly helped the learning process." Merryfield also found that Web-based interaction allows discussion of sen- sitive and controversial topics that would be difficult