Despite the availability and increasingly widespread use of ancillary textbook materials, so far only limited research has explored their impact on learning. Two psychology professors, both teaching the introductory course in that field, decided to explore that impact, specifically in terms of the use of practice tests that are a part of MyPsychLab published by Pearson and ancillary to an introductory psychology text authored by Ciccarelli and White. These professors were motivated by a very pragmatic concern. “Is it worthwhile to require students to purchase access to these resources?” (p. 229)