WASHINGTON (AP) -- In an expanding call for answers, Republicans have joined Democrats in asking the Education Department why the test scores of many minority students are not being counted as promised under the No Child Left Behind law.
The House Education and the Workforce Committee also plans a hearing on the issue.
The Associated Press found last month that nearly 2 million students were not counted when schools reported yearly progress by racial groups. Most of these students were minorities.
"We are concerned that it appears some states may be allowing millions of minority children's scores to be excluded," the committee chairman, Representative Howard McKeon, R-California, wrote Education Secretary Margaret Spellings. "We firmly believe states must not be allowed to continue to do this any longer."
The committee's top Democrat, Representative George Miller of California, signed the letter. So did Representatives Mike Castle, R-Delaware, and Lynn Woolsey, D-California.
The letter, made public Wednesday, was sent to Spellings last week. It follows a similar letter from Miller and 13 other Democratic lawmakers in late April.
Education Department spokesman Kevin Sullivan said the agency welcomes the chance to respond.
"Because of this law, we now know more about 23 million students than we did just a few years ago," he said. "We appreciate the support of Congress as we work with states to reduce the number of students they exclude."
Under the law, schools may exclude math and reading scores when a racial group is too small to be statistically significant, or when the privacy of students could be jeopardized.
But the AP found that some states are setting the minimum group size so high that they do not have to report scores by race even when they have larger numbers of kids.
That, in turn, makes it easier for schools to meet the law's goals and avoid penalties.
The federal government approves the sizes of the racial groups that states set.
The House lawmakers have asked Spellings for answers on how her agency reached those decisions, and how she plans to ensure states are counting as many students as possible.
Excluded scores at the school level may still be counted at the district or state levels.
A House hearing on May 18 will examine whether the law has forced a narrowing of curriculum. A later hearing will focus on racial subgroups.
The law, approved after a strong push from President Bush, is up for renewal in 2007.