In this post I present the IBL levels, a la the Van Hiele levels, which sincere apologies to Van Hiele. These are based on my observations of IBL instructors over the past decade.
A very important point is that the IBL levels presented here are simplistic (reductionist) and are intended as a form of guidance to instructors. The IBL levels indicate the direction in which you ought to go and provide a framework for evaluating your own teaching.
Level 0: non-IBL, teacher-centered instruction.
Level 1: some student engagement via occasional "active lecture" methods like
Think-Pair-Share, concept questions, or students working out examples. The instructor and textbook remain as the predominant mathematical authorities, where students seek confirmation from the instructor or textbook to check if their answers are correct.
Level 2: a significant percentage of class time (50% or more) is used to engage students in solving problems, discussing solutions, and peer reviewing work. The problem solving activities are focused on problems that students do not know the answer to or are not shown the strategy or solution method. Students are supported and encouraged to make their own conclusions, think for themselves, and share their insights. Students have a predilection for determining the correctness of solutions without always seeking external validation from an instructor or book. Students have frequent opportunities to engage in rich mathematical task.
Level 3: full IBL.
While level 3 is a lofty goal to set for oneself for teaching all courses, level 2 is more easily attainable, especially for courses like freshman calculus. Levels 2 and 3 are then goals that can be achieved by math instructors. In particular, level 2 does not require wholesale changes in curriculum, and is thus appropriate for various contexts and environments. It should be noted, however, that level 2 does not have the same potential as level 3 for transformative experiences. There are always tradeoffs.
For novice IBL instructors, you do not have to wait for the "right course" to begin your journey in IBL instruction. Level 1 can be done in any class, and allows you to test the waters and build up your own IBL teaching skills and understanding of IBL methodology. Making the transition to level 2 would be much easier, and it sets the foundation for making the transition to full IBL instruction.
If you have been hesitating, start with level one and try out Think Pair Share!