If you also find it hard to mark qualitatively... here's a tool to make things easier. It's called RUBISTAR and it allows you to set the parameters you want to evaluate or just take them from the ones already designed.
See this example made for a Europe Trip Presentation:
The items on top are written in German but they mean "very well", "well", "ok", "not enough".
I can't stop checking the already-made grids since a friend told me about this application!!!