The results of tasks performed by any user from the LMS main screen are stored in one of two possible places.
If the user is a member of a user group (recommended) then their task results are stored in that user group. See
Viewing user results when the user is a member of a user group.
If the user is not a member of a user group, then their task results are stored in their user account. See
Viewing user results when the user is not a member of a user group.