Our data & methodology

Practice-question answers

Whether each answer was right on the first try, the time spent on the question, whether the student switched answers, and which wrong option they chose.

Flashcard grades

“Know it” or “still learning” for each card, per session.

Study-guide checkpoint answers

The quick check questions at the end of study-guide modules.

Exam dates people set

When someone sets their exam date, we learn how far ahead people start studying — the lead-time figures on each practice page.

Approximate state and local hour

Coarse location (state level) and the local hour of study. No city, no precise location.

Never: names, emails or accounts

The data has no names, no email addresses and no city. A “student” is a browser, not a person.

Repeat attempts

Only each student’s first attempt at each question counts. A question answered for the fifth time says more about memory than difficulty.

Answers after revealing the explanation

If someone peeked at the answer first, that answer is dropped.

Bots

Automated traffic flagged by our bot checks never enters the numbers.

Staff and test accounts

Our own team’s study sessions and QA runs are excluded.

Retired question versions

When we rewrite a question set, answers to the old version stop counting toward the current figures (see hardening, below).