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DP-100 · Question #78

You are performing a filter based feature selection for a dataset 10 build a multi class classifies by using Azure Machine Learning Studio. The dataset contains categorical features that are highly co

The correct answer is D. Person correlation. NOTE: The stated correct answer (D, Pearson correlation) is questionable from a statistical standpoint. Pearson correlation measures the linear relationship between two continuous (numerical) variables. For categorical features correlated with a categorical multi-class label, Chi

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Question

You are performing a filter based feature selection for a dataset 10 build a multi class classifies by using Azure Machine Learning Studio. The dataset contains categorical features that are highly correlated to the output label column. You need to select the appropriate feature scoring statistical method to identify the key predictors. Which method should you use?

Options

  • AChi-squared
  • BSpearman correlation
  • CKendall correlation
  • DPerson correlation

How the community answered

(31 responses)
  • A
    16% (5)
  • B
    3% (1)
  • C
    6% (2)
  • D
    74% (23)

Explanation

NOTE: The stated correct answer (D, Pearson correlation) is questionable from a statistical standpoint. Pearson correlation measures the linear relationship between two continuous (numerical) variables. For categorical features correlated with a categorical multi-class label, Chi-squared (A) is the statistically appropriate method, as it tests independence between categorical variables. Spearman and Kendall are rank-based correlation methods suited for ordinal data. In the context of Azure Machine Learning Studio's Filter Based Feature Selection module, the scoring method must match the data type - if the exam intends that the features or label are treated as continuous, Pearson applies, but for purely categorical features with a categorical label, Chi-squared is the correct choice. Many exam versions flag this as a known answer-key discrepancy.

Topics

#Feature Selection#Correlation#Categorical Data#Azure Machine Learning

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