Like any theory, the transactional distance model serves as a heuristic device, a means of identifying questions for research and also a very practical instrument to be used in making these difficult instructional design decisions.
Regardless, these variables interact to create transactional distance which Michael G. Moore defines as “a psychological and communication space to be crossed, a space of potential misunderstanding between the inputs of instructor and those of the learner.” Thus, the utility of the theory is that it provides guidance to instructional designers as to how to design the course: e.g. how much structure, dialog, and autonomy to build into the course, so as to minimize transactional distances and thereby maximize learning outcomes.
Aixu (Monica) Zhang built on Michael G. Moore's theory by proposing that transactional distance could be viewed as a measure of the student's difficulty in becoming actively engaged with their online learning environment.
She found that these four sets of variables were highly and statistically correlated with Student Satisfaction, which she adopted as her surrogate measure for Transactional Distance.
Relative Proximity Theory borrows from gap, or needs analysis (Kaufman & Guerra, 2013) to yield the transactional distance between an actual and desired state.
Coll-TD/F Scale (Swart et al., 2015): This instrument extends the Coll-TD Scale to Flipped Classrooms where collaboration takes place both f2f, during interactive group learning sessions, and outside class (virtual or f2f) during collaboration on projects or take home exams.