WE like to think we live in the information age, when daily or even second-by-second statistics on such fare as stock prices and the annual number of homicides are at our fingertips. For all the careful accounting, however, there are two figures Americans don't have: the precise number of people killed by the police, and the number of times police use excessive force.

Despite widespread public interest and a provision in the 1994 Crime Control Act requiring the Attorney General to collect the data and publish an annual report on them, statistics on police shootings and use of nondeadly force continue to be piecemeal products of spotty collection, and are dependent on the cooperation of local police departments. No comprehensive accounting for all of the nation's 17,000 police department exists.

This lack of accurate statistics makes it virtually impossible, experts say, to draw meaningful, big-picture conclusions about deadly encounters between the police and the civilian population, including the fatal shooting earlier this month of an unarmed black man in Cincinnati, an incident that incited days of violent protests and vandalism. Without a national barometer, there is no conclusive way to determine whether this or other incidents around the country -- like those involving Amadou Diallo in New York and Rodney King in Los Angeles -- represent racially based police misconduct, or any kind of trend at all.

The major reasons for the vacuum, the experts agree, are twofold. The lack of information on police shootings is attributable to the failure of police departments in many cities to keep and report accurate figures that distinguish between what the police see as ''justifiable'' shootings -- those in which the suspect posed a serious threat -- and incidents where an officer may have unlawfully fired at an unarmed civilian.

The International Chiefs of Police, a police organization, tried in the 1980's to collect such information, but ''the figures were very embarrassing to a lot of police departments,'' said James Fyfe, a professor of criminal justice at Temple University who is a former New York City police lieutenant. The results, he said, varied wildly. New Orleans had 10 times as many shootings per 100 officers as Newark. Long Beach had twice as many as neighboring Los Angeles, which in turn had three times more than New York.

Some cities did not provide data at all, Professor Fyfe said, but the results, such as they were, showed that ''the rates of deadly force are all over the lot,'' meaning that some cities appear to be much better and some much worse at managing their police forces.

As for the lack of figures on the use of nondeadly force, the situation is even murkier because there are no uniform definitions of force and no standard reporting requirements from one police department to another.

The Bureau of Justice Statistics, the statistical arm of the Justice Department, has tried to fill in some of the blanks on police behavior, issuing a number of surveys and reports on the topic. Most recently, the bureau quietly released a report, ''Policing and Homicide, 1976-1998.'' But the report itself underscores the continued problems in knowing what is really happening.

On its cover, for example, the report refers to all the victims of police shootings as ''felons justifiably killed by police,'' a categorization that Samuel Walker, a professor of criminal justice at the University of Nebraska at Omaha, termed ''deeply offensive and legally incorrect.'' In fact, a Justice Department official said the bureau was so embarrassed by the term, and the lack of distinction between justifiable police shootings and murders, that it did not send out its usual promotional material announcing the report.

BUT, the official said, the bureau was trapped because it depends on local police departments to report their figures on police shootings to the Federal Bureau of Investigation, and ''felons'' is the term that police departments insist on using when they do so.