Curriculum sequencing tutors are based on the cognitive theory of knowledge spaces by Jean-Paul Doignon and Jean-Claude Falmagne of the University of California at Irvine. The tutors guide a student through learning material. Curriculum sequencing tutors do not make a detailed assessment of a student’s skills through model tracing, like cognitive tutors. Rather, curriculum sequencing tutors make a general assessment of student skills. The tutors form an assessment of a broad range of skills with the least possible evidence. This requires that skills be explicitly linked together with prerequisite skills appropriately identified. A commercial spin off of curriculum sequencing tutors is the ALEKS tutors for math and accounting (Desmarais & Baker, 2012).