A growing number of child abuse or neglect reports in Virginia are false, according to a new state study. But the reports that are valid often involve problems, such as sex abuse, that are more serious than those reported in the past.

The number of unfounded reports has risen 300 percent since 1978 -- three times the increase in the number of reports overall, according to Lynne Edwards, a child welfare specialist in the Department of Social Services, which conducted the study. Last year, fully 71 percent of all Virginia reports were declared invalid.

Fairfax County has experienced the same phenomenon with baseless accusations. In 1984, they made up almost 70 percent of the social workers' caseloads, compared with only 43 percent four years earlier, according to William McDonnell, assistant director for child welfare services for the county.

At the same time, the number of sex abuse cases has increased tenfold in the state since 1975. "The increase in what you would consider serious cases has been dramatic," Edwards said.

Edwards attributes the rise in unfounded reports partly to more discriminating investigators, who no longer waste their time on cases that they found worthy of following in the past, though, by state law, they must investigate every complaint.

For instance, Edwards said that investigators probably open far fewer of the so-called "dirty kid" cases now than they did six years ago, partly because they don't have time given their increasing caseloads and partly because philosophies of social work have changed.

"It could be that things we looked at 10 years ago as serious we now see in a different light," said Edwards. "We're not in the business now of trying to make everyone middle-class families."

Fairfax's McDonnell said an increased focus on training in recent years has helped his workers decide better which cases have merit.

Some of the increase in false reports may be coming from family members, neighbors, or ex-spouses seeking leverage for custody battles, who deliberately file the accusations, state and local social workers said. No one knows how many erroneous calls they account for, but "they are a factor," Edwards said.

For busy social workers, the deluge of invalid complaints poses a significant problem -- but state officials and legislators are wary of trying to screen out any complaints without an investigation.

"We don't like to get into unfounded situations," said Ray Goodwin, deputy commissioner for social services. "But any time you start screening cases, there's always the chance that you will miss a situation in which a child is being injured."

The state's current approach is to gather more information on those who make false reports. Edwards is trying to figure out how to collect more information when a complainant calls.

Virginia also has volunteered to participate in a study by the University of California aimed at identifying common characteristics of baseless reports by nonprofessionals, Goodwin said.

Del. Sam Glasscock (D-Suffolk) sees the rising number of unfounded complaints as good reason not to change the protections in the current law for those accused.

Glasscock, who chairs the House Committee on Health, Welfare and Institutions, sees "a move afoot" to toughen the law now and expects to see legislation introduced to that effect in the next General Assembly.

He said citizens in Newport News have circulated petitions, for instance, for ruling out plea bargains in child abuse cases.

"I don't feel that would be good change," Glasscock said. "I think the figures on unfounded accusations argue for maintaining a good system with a lot of checks and balances."