WASHINGTON - If Congress doesn't get the job done, Education Secretary Margaret Spellings says she'll consider using her authority to require states to report high-school graduation rates in a more uniform and accurate way.

"I think we need some truth in advertising," Spellings said in an interview, referring to the hodgepodge of ways states now report graduation data.

States calculate their graduation rates using all sorts of methods, many of which critics say are based on unreliable data about school dropouts.

Republicans and Democrats in Congress have drafted proposals to better gauge how well high schools are doing at getting students diplomas, and doing it on time. The changes are part of a rewrite of the No Child Left Behind education law, but that bill's progress has stalled amid disputes over unrelated testing and teacher-pay issues.

Spellings said if that standoff persists, her department has the power to address the reporting of graduation rates. "I think it can be done through regulations," she said.

There is an overwhelming consensus among politicians, educators and academics that states must do a better job. Spellings pointed to a two-year-old agreement by the nation's governors to adopt a common method of calculating high-school graduation rates.

It calls for states to develop systems that track individual students throughout school and record whether they transfer, drop out or graduate.

In general, students who graduate on time and with regular diplomas would count toward a state's graduation rate. Research indicates students who take extra time to graduate or get alternatives to diplomas, such as a GED, generally don't do as well in college or the work force.