Recipe for "success"

At least some level of success, as in a passing grade for the marking period at the very least.

I always assumed there was a correlation between completed work and grades but now I have a little data to back it up, thanks to the magic of electronic gradebooks and excel. I noticed it almost by accident as I was sorting grades the other day. Let's get the graphic out of the way:

Sorry it's a bit fuzzy, I'm not sure what is the best method for converting an excel chart into a jpeg for posting on the internet - if I figure it out I'll come back & fix it.(See Update)

Missing assignments are on the X axis, grades on the Y. The general trend is pretty obvious and allows me to make a few generalizations. Trendline shows a clear negative correlation between missing work and grades - As missing assignments increase, grades decrease.*

1. Although it is not an official policy of mine, it seems virtually, mathematically impossible to fail my class if you do all the work. Based on this observation, I'm now willing to make it official policy - I guarantee you will receive a passing grade if you DO all your work. Of course this does not include work copied from a friend just to hand something in or habitually late work (as in a week after the marking period ends!).

2. More work = higher grades. Of the relatively small number of students who have zero missing work, the grades range from 84-101 (I give extra credit occasionally). One missing assignment and the range goes to 72-98. And so on. It's not a perfectly smooth trend, as some assignments carry more weight than others. Some reasonably diligent students still get low test scores and some less-than-diligent students do really well on tests and quizzes. Still the trend is clear.

3. Finally, it's never been my policy to fail a student just because X number of assignments is missing. But as I think more and more about what success means in the real world (It's not what you know but what you do), I'm planning on revising that policy. I don't know exactly what X will be, yet, but I will impose a minimum amount of work requirement from now. Failure to complete that minimum will result in a failing grade regardless of how the numbers compute.

*Yes, I'm aware that there's a certain "duh" factor here. Every assignment not turned in counts against your grade so of course there would be a correlation. But as obvious as it is, I can only conclude that this realization simply hasn't dawned on many of the students who turn in no work and then come to me full of desperate hope that they will somehow still receive a passing grade. So I'm actually using this data in class to have students look at, think about, and discuss what it takes to succeed.

UPDATE

It looks like GIF is the way to go with charts. Click on the small picture above to see larger (clearer) version. I copied the chart from excel and pasted into photoshop (elements), saved as GIF.