Her primary work focuses on the development of measures of content knowledge for teaching mathematics, and using such measures to evaluate public policies and programs intended to improve teachers' facility with mathematics. Her other interests include the measurement of instruction more broadly, instructional improvement efforts in mathematics, and the role that language plays in the implementation of public policy. She received a Ph.D. in political science from the University of Michigan in 2000 for work analyzing the implementation of public policies in law enforcement and education.She is the co-author, with David K. Cohen, of Learning policy: When state education reform works (Yale Press, 2001). See her personal website, www.umich.edu/~hhill, for papers.