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An Approach to Reduce the Number of Conditional Independence Tests in the PC Algorithm

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Part of the Lecture Notes in Computer Science book series (LNAI,volume 12873)


The PC algorithm is one of the most prominent constraint-based methods for learning causal structures from observational data. The algorithm relies on conditional independence (CI) tests to infer the structure and its time consumption heavily depends on the number of performed CI tests. We present a modification, called ED-PC, such that – in the oracle model – both ED-PC and the original PC algorithm infer the same structure. However, by using a new idea allowing the detection of a v-structure without explicit knowledge of a separating set, our method reduces the number of needed CI tests significantly. This is made possible by detecting nonadjacencies considerably earlier.


  • Graphical models
  • Causality
  • Bayesian networks

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  1. 1.

    For exact definitions of the notions used in the algorithm, see Sect. 2.

  2. 2.

    We use iff as shorthand for “if and only if”.


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This work was supported by the Deutsche Forschungsgemeinschaft (DFG) grant LI634/4-2.

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Correspondence to Marcel Wienöbst .

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Wienöbst, M., Liśkiewicz, M. (2021). An Approach to Reduce the Number of Conditional Independence Tests in the PC Algorithm. In: Edelkamp, S., Möller, R., Rueckert, E. (eds) KI 2021: Advances in Artificial Intelligence. KI 2021. Lecture Notes in Computer Science(), vol 12873. Springer, Cham.

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