While Jennifer was at home taking an online exam for her business law class, a monitor a few hundred miles away was watching her every move. Using a web camera equipped in Jennifer's Los Angeles apartment, the monitor in Phoenix tracked how frequently her eyes moved from the computer screen and listened for the secret sounds of a possible helper in the room. Her Internet access was locked - remotely - to prevent Internet searches , and her typing style was analyzed to make sure she was who she said she was: Did she enter her student number at the same speed as she had in the past? Or was she slowing down? In the battle against cheating, this is the _ and a key to encourage honesty in the booming field of online education. The technology gives trust to the entire system, to the institution and to online education in general. Only with solid measures against cheating, experts say, can Internet universities show that their exams and diplomas are valid - that students haven't just searched the Internet to get the right answers. Although online classes have existed for more than a decade, the concern over cheating has become sharper in the last year with the growth of "open online courses." Private colleges, public universities and corporations are jumping into the online education field, spending millions of dollars to attract potential students, while also taking steps to help guarantee honesty at a distance. Aside from the web cameras, a number of other high-tech methods are becoming increasingly popular. Among them are programs that check students' identities using personal information, such as the telephone number they once used. Other programs can produce unique exam by drawing on a large list of questions and can recognize possible cheaters by analyzing whether difficult test question are answered at the same speed as easy ones. As in many university classes, term papers are scanned against some large Internet data banks for cheating. Some programs can find out possible cheaters by   _  .
checking the question answering speed producing a large number of question scanning the Internet test question giving difficult test question