The Circumplex Model focuses on the three central dimensions of marital and family systems: cohesion, flexibility and communication. The major hypothesis of the Circumplex Model is that balanced couple and family systems tend to be more functional compared to unbalanced systems. In over 250 studies using the Family Adaptability and Cohesion Scales (FACES), a linear self-report measure, strong support has been found for this hypothesis. In several studies using the Clinical Rating Scale (CRS), a curvilinear observational measure, the hypothesis was also supported. These two assessment tools, the FACES and the CRS, are designed for research, clinical assessment and treatment planning with couples and families.