A habit tracker says study, but one tick represents reading a page and another represents a full lesson. Looking back, you cannot tell what the record describes.
Choose a simple meaning for the mark. It might record that you completed one exercise or spent a planned period with the material. Keep the definition close to the tracker so you can use it consistently.
Leave room for variation
If sessions differ substantially, add a brief note instead of forcing them into the same measure. A short session may still be useful even if it does not meet your original threshold. You can record it separately and review whether the threshold fits.
Check whether tracking helps you return to the practice or makes you avoid it when a mark seems unlikely. You can simplify or stop the tracker if it adds pressure without useful information. Keep the activity itself visible in your review: what did you practise, what changed, and what would make the next session easier to begin?


