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Exploratory Data AnalysishardMultiple ChoiceObjective-mapped

MLS-C01 Exploratory Data Analysis Practice Question

A data scientist is analyzing a dataset with a binary target variable. The dataset is highly imbalanced (99% negative class). Which metric is most appropriate for evaluating the model's performance during exploratory data analysis?

Answer choices

Why each option matters

Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.

Correct answer & explanation

Area Under the ROC Curve (AUC-ROC)

In highly imbalanced datasets (99% negative class), accuracy is misleading because a model that predicts the majority class always achieves 99% accuracy. Precision focuses on false positives and is threshold-dependent. F1 score balances precision and recall but is sensitive to the chosen threshold and may not reflect overall performance. AUC-ROC evaluates the model's ability to distinguish between classes across all thresholds and is robust to class imbalance, making it the most appropriate metric for initial model evaluation.

Answer analysis

Option-by-option breakdown

For each option: why learners choose it and why it is or isn't the right answer here.

  • Accuracy

    Why it's wrong here

    Accuracy is misleading because a model predicting all negatives would achieve 99% accuracy.

  • Precision

    Why it's wrong here

    Precision alone does not capture recall trade-off.

  • F1 Score

    Why it's wrong here

    F1 score is useful but depends on threshold; AUC-ROC is better for initial exploration.

  • Area Under the ROC Curve (AUC-ROC)

    Why this is correct

    AUC-ROC is insensitive to class imbalance and provides a global measure of performance.

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Last reviewed: Jun 20, 2026

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