Titles can alter the comprehension of a text by affecting the selection of information from a text and the organization of this information in memory. Text comprehension is assumed to involve an organizational process that results in the formation of a text base, an ordered list of semantic units-propositions. The text base can be used as a retrieval scheme to reconstruct the text. Procedures for assigning propositions as more relevant to some themes as compared to other themes are developed and applied to texts. Texts with biasing titles were used in an experiment to demonstrate that immediate free recall is biased toward the theme emphasized in the title. The comprehension process which is guided by the text's thematical information is described.