CL only predicts when we are satisfied with membership in a given relationship, or group. Therefore, Thibaut and Kelley also say that people use a CL for alternatives to evaluate their outcomes. Basically, CL for alternatives is determined by "the worst outcome a person will accept and still stay in a relationship." As such, comparison level for alternatives is a better predictor for whether or not a person will join or leave a relationship, or group. However, even if a relationship is unhealthy, a person might choose to remain in it because it is better than what they perceive the real world to be.