Posts

https://medium.com/@niejiayang32/common-methods-to-select-features-with-pros-and-cons-efd71e2a1f01

The time complexity for using the closed-form solution is very high. In R, unlike other package that uses gradient descent, R borrows the powerful Frisch-Waugh-Lovell Theorem to reduce the computational cost.

Bias-Variance Trade-off is usually used to explain accuracy v.s. overfitting tradeoff. However, it is not rigorous and difficult to correlate overfitting with variance. Here is my version of explaining this. Of course, there is not much innovation here and many people could have thought in the same way.

This article shows why K-means is a special version of Guassian Mixture Model.

A thorough summary of the few assupmtions for Linear Regression and what to do when those assumptions are not met,

A/B testing is a powerful decision-making tool. However, if social network spill-over effect exists, then the average treatment effect will be underestimated. This is because the control group will also be exposed to some condition of treatment.

The degree of freedom represents the number of “free” or independent $N(0,1)^2$ in the residuals from linear regression.