Advantages of Weighted KNN (WDKNN) Over KNN

Raghda Al taei
2 min readOct 13, 2024

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The K-nearest neighbors (KNN) algorithm is widely used for classification tasks, but it has limitations, especially with imbalanced datasets. The paper “An Improved KNN Algorithm Based on Minority Class Distribution for Imbalanced Dataset” introduces Weighted KNN (WDKNN) as an enhanced version of KNN. Here’s how WDKNN improves upon KNN:

1. Focus on Minority Classes

WDKNN gives more weight to the minority class instances during classification. This adjustment helps counteract the bias KNN often exhibits toward the majority class, leading to improved predictions for underrepresented data points.

2. Improved Classification Accuracy

By emphasizing the influence of important minority instances, WDKNN can achieve higher classification accuracy, particularly in imbalanced scenarios. This makes it a more effective choice for applications where minority class prediction is critical.

3. Dynamic Weighting

In WDKNN, the weights assigned to neighbors can be dynamically adjusted based on their distance from the query point. Closer neighbors have more influence, ensuring that the most relevant instances impact the classification outcome more significantly than distant ones.

4. Reduced Overfitting

The weighted approach helps mitigate overfitting by preventing the model from overly relying on the majority class instances. This balance leads to a more generalized model that performs better on unseen data.

Conclusion

The paper “An Improved KNN Algorithm Based on Minority Class Distribution for Imbalanced Dataset” clearly demonstrates the advantages of WDKNN over traditional KNN. By focusing on minority class instances, enhancing classification accuracy, utilizing dynamic weighting, and reducing overfitting, WDKNN offers a more robust solution for dealing with imbalanced datasets. These benefits make WDKNN a powerful alternative for practitioners facing classification challenges.

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Raghda Al taei
Raghda Al taei

Written by Raghda Al taei

Data Scientist/Analyst Specialist | Johns Hopkins University Master’s Degree in Computer Engineering (AI) | Amirkabir University

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