I have read Gee before, but not his chapter SEMIOTIC DOMAINS: IS PLAYING VIDEO GAMES A “WASTE OF TIME”?.” In the chapter, he develops a rich definition of critical learning and its relationship to semiotic domains.

For active learning, the learner must, at least unconsciously, understand and operate within the internal and external design grammars of the semiotic domain he or she is learning. But for critical learning, the learner must be able consciously to attend to, reflect on, critique, and manipulate those design grammars at a metalevel. That is, the learner must see and appreciate the semiotic domain as a design space (40).

The definition of critical learning considers active learning as an elementary consideration of the types of learning possible in the classroom. Although video games may not be the medium in which I have students engage in critical learning, I appreciated how careful Gee is in his definitional work. The five principles that he closes the chapter with are especially helpful when considering other opportunities for learning with visuals. I could imagine using these to design a class on new media, print media, and document design.