Active Grading: Scale Matters

A colleague of mine uses a 0% – 100% scale, but never gives anything below a 50% for any reason. So when a student answers that George Bush was the first president of the United States, he gets a 50%.  When a student doesn’t even hand in an assignment, she gets a 50% – not a zero.

Let’s picture it!

The traditional 0-100 scale:

The 50-100:

So clearly there’s an aesthetic advantage.  It’s just nice to have the grades spread out over our scale, isn’t it?  But there’s some mathematical beauty in here too.  In the first scale, a terrible grade averaged with a great grade makes… a terrible grade!  In the second scale, a terrible grade averaged with a great grade makes… a mediocre grade!  This is a huge selling point for me.  If you’re averaging your students’ scores, no longer do they have to earn THREE PERFECT SCORES to bring a single zero up to a SEVENTY-FIVE.

Also, I love the change in focus from the first scale to the second.  The first one has a huge red zone – so many scores that are failing.  The second one is mostly “you’re doing well” and “you’re getting there,” with only the room needed reserved at the bottom for “you’re failing.”

It feels a little weird giving anything but a zero for a totally negative assessment, but this is mathematically identical to making 50 the top score and 0 the bottom score.  Or having a 5-point scale:

If you’re looking for a way to progressify your grading scale a little bit and the rest of your school goes from 0-100%, or you’re mid-way through your class and you want to change a little without a lot of commotion… just stop giving zeroes!


This is cross-posted from the ActiveGrade blog.  ActiveGrade is the software I’m creating to support all of these new-fangled SBG ideas that make so much sense.  Though I’ll probably cross-post most articles that are relevant to the Point of Inflection themes, if you want to catch all of the updates to the program make sure to subscribe over there too.  Thanks for reading!