| 2008 | RO-MAN | Semantic category acquisition in dialogue for interactive object learning. | Hartwig Holzapfel, Daniel Neubig |
| 2007 | Interspeech | Behavior models for learning and receptionist dialogs. | Hartwig Holzapfel, Alex Waibel |
| 2006 | Interspeech | A multilingual expectations model for contextual utterances in mixed-initiative spoken dialogue. | Hartwig Holzapfel, Alex Waibel |
| 2006 | Interspeech | Rapid simulation-driven reinforcement learning of multimodal dialog strategies in human-robot interaction. | Thomas Prommer, Hartwig Holzapfel, Alex Waibel |
| 2006 | KI | A Robot Learns to Know People - First Contacts of a Robot. | Hartwig Holzapfel, Thomas Schaaf, Hazim Kemal Ekenel, Christoph Schaa, Alex Waibel |
| 2005 | Interspeech | Clarification questions to improve dialogue flow and speech recognition in spoken dialogue systems. | Ulf Krum, Hartwig Holzapfel, Alex Waibel |
| 2004 | ICMI | Implementation and evaluation of a constraint-based multimodal fusion system for speech and 3D pointing gestures. | Hartwig Holzapfel, Kai Nickel, Rainer Stiefelhagen |
| 2004 | Interspeech | Tight coupling of speech recognition and dialog management - dialog-context dependent grammar weighting for speech recognition. | Christian Fgen, Hartwig Holzapfel, Alex Waibel |
| 2004 | IROS | Natural human-robot interaction using speech, head pose and gestures. | Rainer Stiefelhagen, Christian Fgen, Petra Gieselmann, Hartwig Holzapfel, Kai Nickel, Alex Waibel |
| 2002 | ICMI | Integrating Emotional Cues into a Framework for Dialogue Management. | Hartwig Holzapfel, Christian Fgen, Matthias Denecke, Alex Waibel |