Although most alcohol researchers agree that alcohol users represent a heterogeneous group (Babor et al., 1992; Chang & Martin, 2001; Morey, Skinner, & Blashfield, 1984), there have been a wide variety of strategies proposed to represent this heterogeneity. One important source of heterogeneity in samples of individuals with alcohol-related problems involves the severity of these problems. While research attempting to match alcoholics to treatments on the basis of various typological characteristics has met limited success (Kadden et al., 2001; Ouimette, Finney, & Moos, 1997; Project MATCH Research Group 1997a, b), it is possible that hypothesized effects have been obscured because a critical factor underlying client heterogeneity—the severity of alcohol dependence—has not been adequately conceptualized and measured.
