# ML Wiki

## Chi-Squared Ranking

The $\chi^2$ statistics measures the lack of independence between $f$ and $y$ and can be compared to $\chi^2$ with one degree of freedom

it's zero when $f$ and $y$ are independent

$\chi^2$ measures how the results of an observation differs from the result expected according to the null hypothesis

• lower values indicate less dependency
• so for $\chi^2$ we want to take biggest values