National Assessment of Educational Progress (NAEP)

National Assessment of Educational Progress (NAEP) The National Assessment of Educational Progress (NAEP), also known as "the Nation's Report Card," is the only nationally representative and continuing assessment of what America's students know and can do in various subject areas. Since 1969, assessments have been conducted periodically in reading, mathematics, science, writing, U.S. history, civics, geography, and the arts. National Assessment of Educational Progress (NAEP)

FAQs
A: That message indicates that the regressor matrix is not of full rank.

When using dummy variables, the most common cause of this condition is including one variable for each category, rather than excluding one category. When you do this, the set of dummy variables is perfectly collinear with the constant term. Instead, you should exclude one category and interpret the coefficients associated with the others as the difference from the excluded category