The conceptual framework for research on mass-media effects has evolved from a research interest in agenda-setting. Agenda-setting is a concept that derives from the theoretical work of political scientists who explored how and why certain issues emerged from the interplay of group politics. "Agenda-setting" has come to mean the inquiry into how issues receive serious attention by authoritative decisionmakers. The agenda-setting conceptual framework allows researchers to determine when specific issues depicted by the media become more salient to the public or to particular segments of the public. Recently, researchers have questioned the assumptions of the agenda-setting framework. An ecological view has emerged that perceives a collective process of interacting and often reciprocal influences between media and policymakers that helps create a climate that determines the likely composition of the public agenda. This model expresses reverberating effects among the media, the public, and policymakers. This model makes empirical research more difficult, but more accurately captures the diversity of the media's role in shaping the public agenda. In the criminal justice area, media-effects research has evolved in two strands. One focuses on the media's effect on policymaking and on shaping public opinion on criminal justice issues. The second strand examines the media's impact on the adversarial process. Several recent studies have shifted focus from media effects on attitudes to effects on policy outcomes. 43 references.