The goal of this study is to identify the multiple ways in which instructors take advantage of a feature designed into university textbooks that seeks to invite students to get acquainted with the content prior to attending the class in which such content will be discussed. We present an analysis of teacher instrumentation of this feature, which we call questioning devices, using data from 15 instructors who taught calculus, linear algebra, or abstract algebra over one semester. The instructors taught at 14 different universities in the United States. We identified four utilization schemes of the questioning devices in which instructors: completed questioning devices for pre-planning, required students to complete the questioning devices for the purpose of lesson planning, used the questioning devices for the purpose of instruction, and required students complete the questioning devices for the purpose of assessment. These schemes are supported by various operational invariants related to self-perception as competent instructors and implicit theories of teaching and learning. The identified utilization schemes inform textbook developers and author-designers, making them aware of whether these features fulfill their design purposes, and possibly think about changes that might be needed to support instructors in achieving their instructional goals and improve learning. We suggest some further areas of inquiry.