As mentioned before, I do 5 endgame training exercises every day on chesstempo.com. The web site chooses endgame problems based on my current endgame rating. Problems are scored by how accurately the problem is solved, with inferior moves lowering the problem score. Examples:
The first move is ChessTempo's, often an incorrect move. Problems last until checkmate, the capture of a piece that simplifies the endgame puzzle or a bad move that allows a forced draw. A negative score can result by too many inferior moves or by moving into the forced draw. ChessTempo uses an endgame database to score the moves.
In both these problems, I made one or more inferior moves, but did receive a positive score for successful completion. The moves shown in the examples are the correct ones.