[Excerpt] The use of alternative dispute resolution (ADR) practices has become commonplace in many large American firms. A growing number of organizations are turning to various ADR methods designed to deal with inevitable organizational conflicts and disputes. Much has been written about the implications this dramatic change has had for employers, managers, and their employees. Nevertheless, despite ADR's prevalence and the extensive research documenting its organizational manifestations, many empirical questions remain regarding the factors and pressures that have brought about this substantial transformation in the way organizations manage and address workplace conflict. ADR scholars have developed a number of theoretical frameworks in an attempt to better explain the widespread diffusion of ADR in the United States and in other developed countries. At the heart of this research is an attempt to isolate central predictors of organizational use of different dispute resolution approaches. Why do some organizations use ADR practices, while others choose to rely on traditional litigation or managerial authority to resolve workplace disputes? This study contributes to the effort to understand the adoption of workplace ADR by examining the relationship between the union status of the employer and a number of measures of ADR adoption and practice in large U.S. corporations. Since the 1970s, large employers in the U.S. have pioneered the use of ADR to resolve workplace disputes, and it is obviously of central interest to understand what role the union status of the firm may have played in promoting or deterring the widespread adoption of ADR.