Are these pruning conditions acting simultaneously? Or is there a sequence?

AP
AP New Altair Community Member
edited November 2024 in Community Q&A
Are these pruning conditions acting simultaneously? Or is there a sequence?
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  • AP
    AP New Altair Community Member
    Answer ✓
    are all the postpruning conditions to be satisfied?

Answers

  • BalazsBaranyRM
    BalazsBaranyRM New Altair Community Member
    Hi!

    Prepruning is a set of decisions made before doing a split in the decision tree. The constraints specified in the parameters are used to decide if a split is even being done or not. For example, if minimal size for split applies (the leaf already consists of less than 4 elements), no further processing is done on this part.

    "Pruning" is actually postpruning. It does the split and calculates a statistic measure for its quality. If the confidence threshold is not met, the split will be undone.

    So obviously prepruning is before postpruning, and the simple rule-based decisions (minimal size for split) are done before attempted before doing a split attempt.

    Regards,
    Balázs
  • AP
    AP New Altair Community Member
    Answer ✓
    are all the postpruning conditions to be satisfied?
  • BalazsBaranyRM
    BalazsBaranyRM New Altair Community Member
    There is only one in your screenshot, but yes, all conditions need to be satisfied.