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K-Fold Cross-Validation Visualization

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About This MicroSim

This interactive visualization demonstrates how K-fold cross-validation works by showing how a dataset is partitioned into K equal-sized folds, with each fold taking turns as the validation set while the remaining folds form the training set.

How to Use

  1. Adjust K: Use the slider to change the number of folds (3-10)
  2. Next Fold: Step through each fold one at a time
  3. Run All Folds: Automatically animate through all K folds
  4. Reset: Return to the initial state

Key Concepts

  • Training Folds (Blue): Data used to train the model in each iteration
  • Validation Fold (Orange): Data used to evaluate the model in each iteration
  • Cross-Validation Score: The mean accuracy across all K folds provides a more reliable performance estimate than a single train/validation split

Educational Value

This visualization helps students understand:

  • How cross-validation ensures every data point is used for both training and validation
  • Why averaging across multiple folds produces more reliable performance estimates
  • The trade-off between K value and computational cost (higher K = more iterations)
  • How cross-validation reduces the impact of lucky or unlucky single data splits

Learning Objectives

Bloom's Taxonomy Level: Understand (L2)

After using this MicroSim, students should be able to:

  1. Explain how K-fold cross-validation partitions a dataset
  2. Describe why cross-validation provides better performance estimates than a single split
  3. Understand the meaning of "K-fold" and how K affects the validation process
  4. Calculate the mean cross-validation score from individual fold results

Technical Details

  • Library: p5.js
  • Responsive: Yes (adapts to container width)
  • Interactivity: Slider control, buttons for stepping/animation
  • Data: Simulated accuracy values for demonstration

Integration

To embed this MicroSim in your course materials:

<iframe src="https://your-site.github.io/docs/sims/kfold-cross-validation/main.html"
        width="100%" height="550px" scrolling="no"></iframe>