I've completed an initial implementation of the Dataform activity grading. Grading a Dataform activity can now be done either in the entry level (as sum/average/max/min/count of entries ratings) or in the activity level (one grade for the whole). When grading is done in the activity level the entry ratings may still be used but will not count for the activity grade. So you could allow students to rate each other's entries on some scale, and use the same or a different scale to assign activity grades. At the moment grading by entries and grading by activity cannot be combined. It's exclusive either or.
Comments/suggestions are welcome.