In course edition statistics, there are fields for students with or without groups. However, the ActiveRecord query for those looks as follows:si ```rb @course_edition.approved_participants.with_project.size ``` This produces an SQL query similar to this: ```sql SELECT COUNT(DISTINCT "users"."id") AS "count_id", "users"."id" AS "users_id" FROM "users" INNER JOIN "course_participations" ON "users"."id" = "course_participations"."user_id" INNER JOIN "memberships" ON "memberships"."user_id" = "users"."id" INNER JOIN "groups" ON "groups"."id" = "memberships"."group_id" LEFT OUTER JOIN "offerers" ON "offerers"."actable_type" = "User" AND "offerers"."actable_id" = "users"."id" WHERE "course_participations"."course_edition_id" = 1 AND "course_participations"."status" = 1 AND "groups"."status" = 2 GROUP BY "users"."id" ``` In other words, this query returns the number of students who: - participate in `@course_edition` - have a group in **any** course edition. This should only consider groups in the current course edition. Other statistics, such as `approved_participants.without_project`, `approved_participants.on_interest_list`, etc. have a similar issue. Suggested fix: instead of following the path `course_edition -> course_participation -> user -> membership`, we could do `course_edition -> project -> group -> membership -> user`