Four experiments involving 54 adults were performed to examine the relationship between the effects of story grammar categories and content centrality on subjects' importance ratings, summaries, immediate recall, and delayed recall. Results of the studies indicated that central content units were judged as more important and were better recalled over time than noncentral content units. Central content was also found to enhance the salience of identical statements contained in internal response and reaction categories and to account for a large portion of the overall story category effect in each experiment, suggesting that the effects of centrality on story content exist independently of the story category in which it is contained. However, reliable story category effects remained after centrality was partialed out in an analysis of covariance, suggesting that the effects of story categories also exist independently of the centrality of the content. These results suggest that both data-driven processing assumed by content centrality and schema-driven processing assumed by story grammars occur during story comprehension. (Author/MKM)