What the data shows
Published College Board AP score distributions differ widely by subject, some exams have far higher 5-rates than others. Difficulty and selectivity vary, and readers calibrate for it: a 5 in a notoriously hard exam reads differently than a 5 in an easier one.
What families should do differently
Balance rigor with direction. A STEM-focused student should take the hardest math and science available (AP Physics C, Calculus BC, Chemistry). A humanities-focused student should take the hardest humanities (AP English, History, Government). Rigor signals most when it lines up with the student's declared interests.
How Tafel uses this
Tafel reads course rigor against the student's direction and flags where the schedule is hard but pointed the wrong way.