To calculate mastery scores, HotKettle uses Weighted Band Accuracy model by default. 

From the uploaded document, we first create a set of questions and categorize them under 8 levels of complexity. Then using the principles of Bloom’s Taxonomy and Master-based learning, we group them first into difficulty buckets and then to a set of conceptual mastery bands, which are: 

Band	Levels	Designation	Focus
A	1 & 2	Foundational	Basic facts, core definitions and simple recalls
B	3 & 4	Application	Using rules/concepts to solve standard problems
C	5 & 6	Analysis	Multi-step reasoning and identifying patterns
D	7 & 8	Advanced	Critical thinking, synthesis, evaluation and edge cases

For each band, we calculate its local score by multiplying the band's weight, accuracy in that band (Correct / Attempted) and a penalty factor which is number of questions attempted in that band x 1/3. If a student attempts fewer than 3 questions in a band, this prevents "fluke" scores where a student gets 1/1 correct answers and claims 100% mastery. 

The final mastery score is then the highest band score that the student has "unlocked".