Interview Q&A / Machine Learning
Machine Learning interview questions
Supervised vs unsupervised learning, overfitting, metrics and the classic models, explained simply.
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- Why is KNN slow at prediction time and poor with many features?
KNN must compare a query against every stored training row, so prediction cost grows with data size. With many features, distances between points become almost equal, so 'nearest' stops meaning much. This is the curse of dimensionality.
IntermediateQuick answer1 min read