To examine the production of programing material in a radio newsroom, a study was undertaken of the sources presented to the newsroom, of sources within the sources, of sources actively sought by the news staff, of degrees of processing of news items, and of the sources comprising the news output. Information in each of these areas was collected at a leading midwestern radio station through one week of informal observation in the newsroom and a two-week case study, employing content analysis, direct observation, and semistructured interviews. A total of 646 sources of news were identified for the period. Results were as follows: the largest source of incoming news was that of the wire services; the other major news source was incoming telephone calls from public and corporate officials and labor spokesmen; public officials dominated the sources of incoming wire copy; the two sources accounting for most of the initial sources of newscast items were wire services and previously prepared newscast items; the news operation was more "reactive" than "active," relying heavily on previously prepared stories, initial sources, and wire services; and, in general, variability was not characteristic of the news sources used by this station. (DF)