This is a shot in the dark since I'm really struggling in understanding how your tables work together, but instead of, "task.task_users.collect{|task_user| task_user.court_user.user.name}" how about, "task.task_users.collect{|task_user| task_user.court_users.user.name}" or this, "task.task_users.collect{|task_user|task_user.users.name}"