Stalking in front of the classroom in measured paces, registering surprise, puzzlement and disdain with an arch of his animated eyebrows, Emmanuel Chatman preaches the gospel of cabdriving in the District.

"People in the District are usually well dressed, educated and middle-class, and are interested in tipping and making you feel good, so you have to be careful of the attitude you take into the street with you," Chatman says to 40 cabdriver applicants poring over zone maps and fare schedules in his class.

"You better be careful," he warns, "because those folks who get mad at you might have the authority to do something about it and you could wind up right back here in this class."

All cabdriver applicants must take the class, which teaches city geography, taxicab regulations and public relations skills. The class was mandated by a law that took effect in March aimed at reducing mounting complaints that many District hackers were flagrantly overcharging passsengers, often rude, unfamiliar with well-known streets and landmarks, refusing to take riders to certain city areas, and were foreigners who knew little English.

Under the law, before a new cabdriver can take the test for a hacker's license he must attend the four-day 12-hour course taught by Chatman. The four days must be taken consecutively.

At the end of each session, students are given an examination that they must pass before they can advance to the next phase of the course.

The law also has more than doubled the number of questions on the hacker's exam, required drivers to post a passenger bill of rights in plain view in the back seat, increased the cost of a license from $5 to $35 a year, and mandated that applicants live in the metropolitan area for one of two years immediately preceding their application.

The new regulations grew out of a bill introduced by D.C. City Council member H.R. Crawford (D-Ward 7), who last year had an experience familiar to many of his constituents who live east of the Anacostia River.

When Crawford and fellow City Council member Wilhelmina Rolark, (D-Ward 8), who also represents an area east of the river, tried to get a taxi home from a banquet at a Connecticut Avenue hotel, at least two cabdrivers refused to take them.

In the first eight months of this year, 750 complaints -- most for failure to transport to a requested destination -- have been filed with the city board that regulates cabdrivers, according to Betty Franklin, chairwoman of the three-member hackers review board. For the same period last year, the board received 1,012 complaints, Franklin said.

Larry Greenberg, director of the city's Department of Public Vehicles, which licenses the approximately 11,000 hackers in the District, said it is unclear why the number of complaints has decreased, but he doubts that it is a result of the new law.

"We think that the course is good and that we will see results, but right now it's too soon to tell," Greenberg said. I don't know if the statistics we have mean anything right now, but I think the taxicab industry is very much aware of the new regulations."

Chatman is no stranger to the taxi business. He drove a cab for 15 years while putting himself through college and eventually earned a doctoral degree. He is a now a full-time accounting instructor at the University of the District of Columbia.

Chatman takes a no-nonsense approach in his taxi class, taught in a UDC classroom at Ninth and F streets NW.

Sometimes Chatman teaches District geography and American culture. During one recent imaginary trip to familarize his class with each fare zone, Chatman mentioned the city dog pound as one of the landmarks in the area, and a student hand went up.

"The dog pound," the student asked, "is that a hotel or something?"

"Sort of," Chatman answered. "It's a temporary hotel for dogs before they depart the universe."

Juan Tejera, 25, one of Chatman's students, said he thinks the class will help him when he takes the hackers exam next month.

"I really want to be a cabdriver because I need a job in the wintertime," said Tejera, who is a part-time landscaper. "I think the class will at least help me understand how to deal with people."

About 400 applicants have taken the class, which costs $25, officials said.

Greenberg said in January the city hopes to hire four full-time hack inspectors to help enforce the city's regulations. Currently the city has only four inspectors to check the estimated 11,000 cabs. The city is also developing a new point system for drivers. Hackers who accumulate too many points may be fined or risk having their licenses revoked or suspended.