human: Given a node-centered hypergraph: <hypergraph>, where nodes represent authors and hyperedges represent groups of authors who co-authored the same paper.

Details of the hypergraph:
Center node: "Coordination of referring expressions in multimodal human-computer dialogue."
  Abstract: This study examines coordination of referring expressions in multimodal human-computer dialogue, i.e. to what extent users’ choices of referring expressions are affected by the referring expressions that the system is designed to use. An experiment was conducted, using a semi-automatic multimodal dialogue system for apartment seeking. The user and the system could refer to areas and apartments on an interactive map by means of speech and pointing gestures. Results indicate that the referring expressions of the system have great influence on the user’s choice of referring expressions, both in terms of modality and linguistic content. From this follows a number of implications for the design of multimodal dialogue systems.

Connected through hyperedge HE-1 (induced by source paper "Children’s convergence in referring expressions to graphical objects in a speech-enabled computer game"):
  with members:
    - "Pitch adaptive MFCC features for improving children's mismatched ASR"

Connected through hyperedge HE-2 (induced by source paper "The efficiency of multimodal interaction: a case study."):
  with members:
    - "A comparison of speech and typed input"

Question: Please tell me which research area the center author belongs to. The 4 classes are: Computer science, Mathematics, Engineering, Economics, Psychology, Business. Directly output the class name.

gpt: Computer science