IN THE QUIET of the transition you can hear the sharpening of polemical swords for the coming debate over social priorities. Many of these weapons will be numbers -- statistics that tell how many of us there are, where and how we live, and on what kinds and amounts of income.

Perhaps you have observed that the participants in this battle often cite authoritative data supporting diametrically opposite conclusions. For example, from some proponents of federal budget cutting you will hear that poverty is no longer much of a problem in America. The number of people with cash incomes below what the government counts as poverty has declined from almost 25 percent of the population in the 1950s to 11 or 12 percent in recent years. If incomes are adjusted to count government benefits provided "in kind" (food, housing and medical benefits) rather than cash, and if other peculiarities of individual circumstance are accounted for, "statistical" proverty disappears almost entirely. But from advocates of social programs, and from simply looking around, you will learn that many people live in conditions that most of us would recognize as poverty. Which side is right?

Both. Government programs have grown enormously, and they have helped measurably to reduce the direst needs. But most of the people moved "above the poverty line" remain very close to the subsistence level of living that it describes. Moreover, an increasing number of poor and near-poor are now totally dependent on government benefits, so that a cutback would have an immediate and sharp effect on their well-being.

Analyses of black economic progress offer similar contradictions. Many economic studies point to a narrowing of the difference between the earnings of blacks and whites. But from the black community come reports that things are getting worse. Again, as a recent Urban Institute study shows, both are correct. On average, earnings are improving for those blacks who are steadily employed. But a large and growing number of blacks are unable to find steady work.

No one can warn you about all the likely debating points, but we do offer a general purpose caution. When you hear two politicians flatly contradicting each other's "facts," remember that both sets of facts may be right, but for different and often complex reasons -- and that what is right for policy may depend crucially on those differences.