My research is focused on psycholinguistics, the study of how comprehenders understand and produce language in real time. More specifically, I'm interested in how syntactic structures are represented and manipulated in working memory during the course of language comprehension and production. My research involves building explicit computational models of how comprehenders retrieve information from linguistic structures and testing the predictions of those models against actual human linguistic performance. This modeling involves combining features of formal probabilistic parsing models with explicit models of human associative memory to derive predictions about processing speed and accuracy. Specific topics I have investigated involve the computation of agreement in online processing, and the retrieval of referents for pronominal elements. Ultimately, I hope to be able to shed some light on the question of why natural language grammars look the way they do.