DATABRICKS-MLA Question 51

Community Discussion

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• Chose A0

  - Correct answer : A — `Imputer` defaults to `strategy='mean'`, so the outlier-sensitive mean is used instead of the median; the code must set `strategy='median'` explicitly to match the intended behavior. A . `pyspark.ml.feature.Imputer` defaults to the mean strategy when `strategy` is not passed, so this code silently fills the skewed column with an outlier-sensitive mean rather than the intended median, and `strategy='median'` must be added explicitly. B . The default strategy for `pyspark.ml.feature.Imputer` is mean, not median, so this code does not already produce the intended behavior and would fill the skewed column with a value pulled toward its outliers. C . `inputCols` and `outputCols` are allowed to differ, which is how a new filled column is created alongside the original; this code's mismatched names are valid and do not cause a `fit`-time error. D . Mode is not the default strategy for `pyspark.ml.feature.Imputer`; the default is mean, so describing this failure as a mode-based fill misidentifies both the actual behavior and the fix needed.