Material in this volume has been organized in five sections: (1) a bibliography of studies related to variables of source credibility (110 empirical studies--listed, classified, and annotated--from 1930 through 1969); (2) abstracts of doctoral dissertations in speech communication, 1970 (in the fields of forensics, instructional development, interpersonal and small group interaction, interpretation, mass communication, public address, rhetorical and communication theory, speech sciences, and theatre); (3) titles of graduate theses and dissertations in speech communication, 1970; (4) a bibliography on communication, rhetoric, and public address for 1970; and (5) an index to titles of graduate theses and dissertations and to abstracts of doctoral dissertations. (JM)