This book documents the proceedings of the Fourth International Conference on Cognitive Modeling (ICCM), which brought together researchers from diverse backgrounds to compare cognitive models; evaluate models using human data; and further the development, accumulation, and integration of cognitive theory. ICCM provides a worldwide forum for cognitive scientists who build computational cognitive models and test them against empirical cognitive data. New features of the conference included the Newell Award for best student paper, the Siegel-Wolf Award for best applied research paper, and a Doctoral Consortium which provided an opportunity for students to meet their peers and mentors and to explore their dissertation work in an intense but friendly, multi-approach environment. These new features, as well as a comprehensive view of the posters presented at the conference are offered in this volume.