A few thoughts on the subject of textbooks from Robert Harrell:
Most evaluators and administrators place a great deal of emphasis on student-centered instruction. Many TCI/TPRS teachers take a hit on this because administrators believe that “student-centered” instruction means that students are doing all of the talking. This is an area for administrator education. TCI/TPRS is student centered because it explores what students bring as their interests, takes student input and incorporates it into the instruction, and responds to students’ questions about the language as they arise.