How does hiding answers work?

It's Yahoo's software, they started using it a bit over a month ago.

Now there's a new filter for answers besides "Oldest" "Newest" "Rated Highest", it's "Relevance".

This software makes its determination as to what it thinks is relevant, and hides the supposedly less relevant answers. The software seems to be basing relevance on the length of the answer and on keywords used from the question.

Another new feature that nobody asked for or particularly wants.

The hidden answers are done automatically by a computerized program that sorts answers according to their relevance in answering a question.

No one knows the exact reasons why some answers get hidden and others don't, Yahoo! has not officially said anything about the relevance sorting.

It seems that one word, or few word answers are often hidden as are answers that don't address the question.