Mastery Learning ( https://en.wikipedia.org/wiki/Mastery_learning ) says that students must achieve a level of mastery (e.g., 90% on a knowledge test) in prerequisite knowledge before moving forward to learn subsequent information. This idea came from Benjamin Bloom and is the philosophy adopted by Khan Academy and others.
The Spiral Approach ( https://www.av8n.com/physics/spiral-approach.htm ) argues that the axiomatic approach is a bad idea. one should plan on revisiting the prerequisites and refining them.
What's the research consensus about the efficacy of these two styles?
Context: We want to design the skills graph of LearnAwesome so that it leads to the most effective learning path for any topic. More about the project: https://github.com/learn-awesome/learn-awesome