Despite a century of history, public diplomacy research has lacked defining conceptual frameworks for two focal constructs, public diplomacy behavior and excellence in public diplomacy management. Without such frameworks, the discipline has focused on historical, ideological, and descriptive research on public diplomacy practices and management. At the same time, research has been instrumental, serving the policy concerns of government by studying what effects public diplomacy programs have, can have, and should have from the paradigm of communication effects.

Consequently, public diplomacy seldom has been studied as a set of dependent variables. Scholars have rarely asked theoretical questions about what factors affect public diplomacy behavior and management. The lack of conceptual frameworks has further discouraged comparative questions about whether and why governments are different or similar in their practices and management of public diplomacy. Even when comparative questions were asked, they lacked methodological frameworks for comparative study on a large scale--of a large number and different types of governments.

To overcome the limitations, this dissertation proposed a conceptual framework for the two focal constructs based on an application of the Excellence study (L. Grunig, J. Grunig, & Dozier, 2002), a program of public relations research. From the perspective of international relations, this study constructed and tested a theory of comparative public diplomacy on how a government's contextual variables-- culture, political system, interest-group system, and interstate dependence-- are associated with her public diplomacy behavior and management. Lastly, this study employed an innovative methodological framework of using embassies as "matching samples" as well as "surrogate governments." Out of 169 embassies in Washington, D.C., 113 embassies participated in a survey that measured their policy communication behavior in the form of press relations and overall management of the public diplomacy function.

This study found that uncertainty avoidance, one of Hofstede's (2001) four dimensions of culture, was the most salient in explaining excellence in public diplomacy. Countries with a low uncertainty avoidance culture were most excellent in public diplomacy management. It also found no significant empirical evidence for linkages between culture and public diplomacy behavior. Of the contextual variables investigated, only the political system had significant associations with public diplomacy behavior. The findings also suggested that electoral and non-democracies have more excellent public diplomacy overall than liberal democracies. In addition, the findings showed that interstate dependence is empirically associated with the outsourcing practices of foreign governments for their public diplomacy through local public relations and lobbying firms. The findings also indicated that the outsourcing practices, in turn, increased the excellence of the clients' (i.e., embassies) public diplomacy behavior.

Moreover, the findings confirmed an empirical convergence between public relations and public diplomacy not only at the level of communication behavior but also at the level of communication management. This dissertation, a macro-replication study having governments as the units of analysis, replicated the normative theory of global public relations (Vercic, J. Grunig, & L. Grunig, 1996). Among other things, this study pioneered the macro-comparative research strategy of studying embassies throughout the world capitals. This methodological framework for comparative public diplomacy should offer a myriad of opportunities for advanced theory building from various theoretical perspectives and research methods.