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AI0-001 AI Models and Data Engineering Practice Question

A team is using k-fold cross-validation to evaluate a model. They observe high variance in performance scores across folds. Which TWO actions are most likely to reduce this variance? (Choose TWO.)

⚠ Common exam trap

The AI0-001 exam often tests the misconception that decreasing the number of folds reduces variance, when in fact the opposite is true—fewer folds increase variance because each training set is smaller and more dissimilar.

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

Increase the number of folds

Increasing the number of folds (e.g., from 5 to 10) means each fold contains more training data, which reduces the variance of the performance estimate because the model is trained on a larger portion of the dataset each time. Stratified cross-validation ensures that each fold maintains the same class distribution as the original dataset, which stabilizes performance scores when the dataset is imbalanced, thereby reducing variance across folds.

Answer analysis

Option-by-option breakdown

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

  • Increase the number of folds

    Why this is correct

    More folds mean each training set is larger and more similar to the full dataset, reducing variance.

  • Use stratified cross-validation

    Why this is correct

    Stratification preserves class proportions across folds, reducing variability due to sampling.

  • Decrease the number of folds

    Why it's wrong here

    Fewer folds result in smaller training sets and higher variance in estimates.

  • Shuffle data before splitting

    Why it's wrong here

    Shuffling is standard and does not directly address variance; it ensures randomness but may not reduce variance.

  • Use a more complex model

    Why it's wrong here

    More complex models increase variance, making the problem worse.

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Written by Johnson Ajibi, MSc IT Security

Senior Network & Security Engineer · founder of Courseiva

This AI0-001 practice question is part of Courseiva's free CompTIA certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the AI0-001 exam.