Kiwi does a thorough job when she urinates. She remains in the box, flicking litter at the spot until it's fully covered. When she poops though, she steps out of the box when she's finished, turns her head the opposite direction, reaches in the box and starts scratching the litter, which seldom reaches the target. The she wipes her paws on the mat outside the box and walks off.
I think it's because the box isn't big enough that where she feels she can handle the job without getting any on herself. I'm not absolutely sure that's the situation, but it sounds good to me.