Except for size and dispersion, all measures are derived from applications of cluster and factor analysis. Evidence of construct validity is provided. The measurements are then related to mean scores on five factors of behavior for sixteen gangs. It is found that less differentiated gangs engage in more property offenses; gangs with stronger primary pattern engage in more conflict and stable sex behaviors; gangs with greater cohesion engage in less property offenses and conflict behaviors. Discussion centers upon a distinction between behavioral and attitudinal cohesiveness. (Author abstract)