I'm familiar with most methods of imputation, such as
mean imputation, and
co-prediction (same as imputation using regression).
But, in this article, on page 2 it mentions "rest known data to impute missing terms".
I have never heard of this method and I'm wondering what it means. I know how to use the $X^2$ test to test for independence, so that analysis is sound.....But, how does one use that for actually filling in the missing values? and what is "rest known data to impute missing terms"?