The main way to make this data more meaningful is to intentionally design assessments for learning (in other words, design assessments so teachers and students can both use the data for improvement) rather than just giving a test because it's something we teachers feel the need to do from time to time, give students an overall score that does not help them improve, and then move on to the next unit.
In the presentation I list several steps concerning how to do this in the classroom, and give examples of how I have done it in my high school science classroom.
Click here for a copy of the handouts from this session.
Hope you enjoy it, and if you have any questions, please feel free to leave them in the comments.