This has come up many times before all over the network, most notably here:

Encouraging people to explain downvotes

and the consensus is that asking people to explain down-votes would be counter productive at best.

All you can do is analyse your answer with fresh eyes and see if there is anything you missed first time round.

This has come up many times before all over the network, most notably here:

Encouraging people to explain downvotes

and the consensus is that asking people to explain down-votes would be counter productive at best.

All you can do is analyse your answer with fresh eyes and see if there is anything you missed first time round.