human: Given a hyperedge-centered hypergraph: <hypergraph>, where the center hyperedge groups authors who co-authored the same paper.

Details of the hypergraph:
Center hyperedge (induced by source paper "PIR 2014 The First International Workshop on Privacy-Preserving IR: When Information Retrieval Meets Privacy and Security"):
  Abstract: On July 11th, 2014 the First International Workshop on Privacy-Preserving IR: When Information Retrieval Meets Privacy and Security (PIR 2013) [1, 2] was held as part of the SIGIR 2014 conference in Gold Coast, Australia. Three invited keynotes were given by Prof. Douglas W. Oard, Prof. Christopher W. Clifton, and Prof. David D. Lewis. There were 6 full papers and 3 short papers presented in the presentation sessions. Finally, there were breakout discussions on determining the future directions of these interdisciplinary fields of IR and privacy/security for our community.

Includes members:
  Member "Privacy-Preserving IR 2015: When Information Retrieval Meets Privacy and Security":
    also connected through other hyperedges:
      (none)

Question: Please tell me which research area the co-authored paper (i.e., the source paper of the center hyperedge) belongs to. The 4 classes are: Computer science, Mathematics, Engineering, Economics, Psychology, Business. Directly output the class name.

gpt: Computer science