Questions tagged [decision-trees]

Use this tag for questions about graphs or models of decisions and their possible consequences including chance-event outcomes, resource costs, and utility.

A decision tree is a flowchart-like structure in which each internal node represents a "test" on an attribute (e.g. whether a coin flip comes up heads or tails), each branch represents the outcome of the test and each leaf node represents a class label (decision taken after computing all attributes). The paths from root to leaf represents classification rules.

A decision tree consists of $3$ types of nodes:

  • Decision nodes - represented by squares ($\square$)
  • Chance nodes - represented by circles ($\circ$)
  • End nodes - represented by triangles ($\triangle$)
97 questions
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Is this binary search tree correct?

I have made a binary search tree from this sequence: 4, 1, 7, 5, 6, 3, 0, 2, 9, 8 And I just want to make sure that it is correct. Starting with 4. Then 1 which is less than 4 so its placed on the left side. 7 is greater than 4 so it becomes the…
Peter
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Why is the value of information gain negative?

Here is a sample dataset. I have to calculate the Information gain in Variable. Am I missing anything as information gain should not be…
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Adverse Selection and Decision Trees

In a group of people 10% are unhealthy but don't know it. Of these 50% will likely need to be hospitalized. Of the 90% that are healthy, 10% will likely need be hospitalized. The cost of hospitalization is $50000. What price of insurance should be…
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Looking for a counterfactual approach to interpreting classification decisions

Suppose you're a surgeon and you are making a decision based on the output of a model. The variables in this model $x_1, x_2,...$ are clinically interpretable, like age, blood sugar, or hemoglobin. Every patient has her own set of these variables,…
Sam
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number of nodes in a decision tree

I don't know how to prove/disprove this: In a decision tree for sort algorithm there are at least $2^{n!}$ nodes. I know that the number of leaves is $n!$
joe
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