Speech communication theorists have defined certain rhetorical characteristics that may improve the use and production of written texts. In order to determine whether social studies textbooks have rhetorical characteristics--containing both content information and the author's attitudes toward it--and whether these characteristics have the desired positive effects on students, two studies were conducted. A typology of metadiscourse was used to describe the types and amounts of informational and attitudinal discourse in nine social studies texts for students from third grade to college level and nine texts written by social scientists for adults, ranging from nonacademic to academic periodicals and monographs. Findings showed consistent differences in the use of informational and attitudinal metadiscourse, with nontextbooks using more attitudinal metadiscourse and appearing more lively than textbooks. In the second study, with 120 sixth graders, a chapter from a social studies textbook was modified by adding informational and attitudinal metadiscourse and interpersonal voice as variables to determine their effects on retention and attitude. No overall significant main effects were found, although results indicated that metadiscourse was helpful for some subgroups of students, depending on whether interpersonal voice was used. (Tables and diagrams are included.) (DF)