Deep cuts to staff and funding in the Department of Education will deal a major blow to the public’s understanding of how American students are performing and what schools can do to improve.

On Tuesday evening, at least 100 federal workers who focus on education research, student testing and basic data collection were laid off from the Department of Education, part of a bloodletting of 1,300 staffers. Outside of government, at least 700 people in the field of social science research were laid off or furloughed over the past week, largely as a result of federal cuts to education research.

The layoffs came just weeks after the latest federal test scores showed American children’s reading and math skills at record lows. Trump administration officials have pointed to those low scores as evidence that the Department of Education had failed.

But now the extent of those cuts raise questions about how the federal tests, which provide the data on how students are doing, will continue.

Other basic information about schools, along with research about what works to improve them, seems most likely to be degraded or to disappear entirely. Many of those who were laid off worked on projects evaluating math and reading instruction, disability supports and other subjects critical to student learning.

And some of the data they collected and analyzed played a crucial role in directing federal dollars to schools.