1 . Despite the ambiguity and confusion surrounding it, the construct of organizational effectiveness is central to the organizational sciences and cannot be ignored in theory and research. All theories of organizations rely on some conception of the differences between effective performance and ineffective performance. At their core, organizational theories try to explain effective performance. Hence, effectiveness has important theoretical relevance. Empirically, effectiveness is usually the ultimate dependent variable for organizational research. Relationships between structure and environment, design and innovation, or adaptation and uncertainty, for example, are important because their results lead ultimately to organizational effectiveness. Pragmatically, consumers, clients, resource providers, managers, regulators, members, and other stakeholders in organizations are continually faced with the need to make judgments about effectiveness. Obtaining the best value, the best return, or the best outcome depends a great deal on judgments about which organization can perform the most effectively.