By almost any measure , there is a boom in Internet-based instruction . In just a few years , 34 percent of American universities have begun offering some form of distance learning (DL), and among the larger schools , it’s closer to 90 percent . If you doubt the popularity of the trend, you probably haven’t . It enrolls 90,000 student , a statistic used to support its claim to be the largest private university in the country.
    While the kinds of instruction offered in these programs will differ, DL usually signifies a course in which the instructions post syllabi(课程大纲), reading assignments , and schedules on Websites , and students send in their assignments by e-mail . Generally speaking , face-to-face communication with an instructor is minimized or eliminated altogether.
    The attraction for students might at first seem obvious . Primarily , there’s the convenience promised by courses on the Net: you can do the work, as they say , in your pajamas(睡衣). But figures indicate that the reduced effort results in a reduced commitment to the course . While dropout rates for all freshmen at American universities is around 20 percent , the rate for online students is 35 percent . Students themselves seem to understand the weaknesses inherent in the setup . In a survey conducted for eCornell , the DL division of Cornell University , less than a third of the respondents expected the quality of the online course to be as good as the classroom course.
    Cleary form the schools perspective , there’s a lot of money to be saved . Although some of the more ambitious programs require new investments in servers and networks to support collaborative software , most DL courses can run on existing or minimally upgraded(升级)systems . The more students who enroll in a course but don’t come to campus , the more the school saves on keeping the lights on in the classrooms , paying doorkeepers , and maintaining parking lots , And there’s evindence that instructors must work harder to run a DL course for a variety of reasons , won’t be paid any more , and might well be paid less.