human: Given a node-centered hypergraph: <hypergraph>, where nodes represent papers and hyperedges represent sets of papers co-cited by a source paper.

Details of the hypergraph:
Center node: "a usefulness based approach for measuring the local and global effect of iir services"
  Abstract: In Interactive Information Retrieval (IIR) different services such as search term suggestion can support users in their search process. The applicability and performance of such services is either measured with different user-centered studies (like usability tests or laboratory experiments) or, in the context of IR, with their contribution to measures like precision and recall. However, each evaluation methodology has its certain disadvantages. For example, user-centered experiments are often costly and small-scaled; IR experiments rely on relevance assessments and measure only relevance of documents. In this work we operationalize the usefulness model of Cole et al. (2009) on the level of system support to measure not only the local effect of an IR service, but the impact it has on the whole search process. We therefore use a log-based evaluation approach which models user interactions within sessions with positive signals and apply it for the case of a search term suggestion service. We found that the usage of the service significantly often implicates the occurrence of positive signals during the following session steps.

Connected through hyperedge HE-1 (induced by source paper "a digital library for research data and related information in the social sciences"):
  with members:
    - "query expansion for survey question retrieval in the social sciences"

Connected through hyperedge HE-2 (induced by source paper "analysis of search stratagem utilisation"):
  with members:
    - "investigating exploratory search activities based on the stratagem level in digital libraries"
    - "contextualised browsing in a digital library s living lab"
    - "analysis of footnote chasing and citation searching in an academic search engine"
    - "a complete year of user retrieval sessions in a social sciences academic search engine"
    - "extending search facilities via bibliometric enhanced stratagems"
    - "scientometrics and information retrieval weak links revitalized"
    - "science models as value added services for scholarly information systems"

Connected through hyperedge HE-3 (induced by source paper "contextualised browsing in a digital library s living lab"):
  with members:
    - "data requirements for evaluation of personalization of information retrieval a position paper"
    - "investigating exploratory search activities based on the stratagem level in digital libraries"
    - "a complete year of user retrieval sessions in a social sciences academic search engine"
    - "extending search facilities via bibliometric enhanced stratagems"
    - "cross concordances terminology mapping and its effectiveness for information retrieval"

Connected through hyperedge HE-4 (induced by source paper "data requirements for evaluation of personalization of information retrieval a position paper"):
  with members:
    - "a complete year of user retrieval sessions in a social sciences academic search engine"

Connected through hyperedge HE-5 (induced by source paper "challenges for measuring usefulness of interactive ir systems with log based approaches"):
  with members:
    - "whose a tool for whole session analysis in iir"

Connected through hyperedge HE-6 (induced by source paper "user interests in german social science literature search a large scale log analysis"):
  with members:
    - "improving retrieval results with discipline specific query expansion"

Connected through hyperedge HE-7 (induced by source paper "a complete year of user retrieval sessions in a social sciences academic search engine"):
  with members:
    - "investigating exploratory search activities based on the stratagem level in digital libraries"

Question: Please tell me which class the center node belongs to. The 40 classes are: cs.NA(Numerical Analysis), cs.MM(Multimedia), cs.LO(Logic in Computer Science), cs.CY(Computers and Society), cs.CR(Cryptography and Security), cs.DC(Distributed, Parallel, and Cluster Computing), cs.HC(Human-Computer Interaction), cs.CE(Computational Engineering, Finance, and Science), cs.NI(Networking and Internet Architecture), cs.CC(Computational Complexity), cs.AI(Artificial Intelligence), cs.MA(Multiagent Systems), cs.GL(General Literature), cs.NE(Neural and Evolutionary Computing), cs.SC(Symbolic Computation), cs.AR(Hardware Architecture), cs.CV(Computer Vision and Pattern Recognition), cs.GR(Graphics), cs.ET(Emerging Technologies), cs.SY(Systems and Control), cs.CG(Computational Geometry), cs.OH(Other Computer Science), cs.PL(Programming Languages), cs.SE(Software Engineering), cs.LG(Machine Learning), cs.SD(Sound), cs.SI(Social and Information Networks), cs.RO(Robotics), cs.IT(Information Theory), cs.PF(Performance), cs.CL(Computation and Language), cs.IR(Information Retrieval), cs.MS(Mathematical Software), cs.FL(Formal Languages and Automata Theory), cs.DS(Data Structures and Algorithms), cs.OS(Operating Systems), cs.GT(Computer Science and Game Theory), cs.DB(Databases), cs.DL(Digital Libraries), cs.DM(Discrete Mathematics). Directly output the class name.

gpt: cs.IR(Information Retrieval)