WASHINGTON -- Education Secretary Arne Duncan told a gathering  of presidents of historically black colleges and universities Wednesday that their institutions are essential to the future of the country's education system -- and that they must do a better job helping students get degrees. That dual message, delivered to the 2009 National Historically Black Colleges and Universities Week Conference here , is consistent with the forceful ideas  put forward this summer by John Silvanus Wilson Jr., the Obama administration's new head of the White House Initiative on Historically Black Colleges and Universities. Duncan filled his speech with praise for the tradition of historically black colleges' doing more with less, preparing generations of black leaders despite often comparatively "meager resources." Other colleges could have much to learn from HBCUs in these lean times, Duncan said, singling out institutions such as Elizabeth City State University and Philander Smith College. But while black colleges will benefit heavily from the economic recovery package and other federal aid, they, like other institutions, will have to become more cost efficient. Duncan also challenged the institutions' effectiveness, noting that the teachers they produce are less likely than their peers to pass certification tests and that many of the colleges have graduation rates below 20 percent, an "unacceptable outcome for students.... And just like other institutions of higher education, HBCUs cannot explain away big differences in graduation rates simply by reference to the usual suspects. The management practices of those colleges have to be part of the explanation -- and part of the solution."