Keith's research examines students’ understanding of topics such as historical agency, historical significance, national identity, and human rights. He has worked with faculty, teachers, and students in the United States, Northern Ireland, Singapore, New Zealand, Chile, South Sudan, Macedonia, Sweden, and other countries. He has also served as a Visiting Professor at the University of Ulster (Northern Ireland), Uppsala University (Sweden), Victoria University (New Zealand), and the National Institute of Education (Singapore), as well as a Fulbright Senior Specialist in New Zealand.