Grades as a Measure of Course Difficulty

This is the current grade distribution for my Social Problems class. It's obviously not the normal curve you're "supposed" to have, but generally I'm okay with a distribution like this, though I'd prefer the modal grade to be a B. About half the class has an A at the moment, and the vast majority have at least a C. Attendance in this class is good. People seem to be paying attention, they contribute and ask questions, nod along, etc.



This is the current grade distribution for my Introductory Sociology class. The modal grade is a B, and all but one student is passing (and that person is an absentee student). I'm generally okay with this, but I'd prefer there to be more C's and a handful of students getting Ds and Fs. These students seem to be just skating by without any effort. (Oh and the Intro students really are skating by - attendance is typically at about 50%, compared to 90% in my 8am Social Problems class).

Why on Earth would it bother me that students aren't doing worse in my classes? Do I want my kids to fail? Well, no. It's more about what those grades imply to me. A more normal distribution makes me think I'm not handing out A's like lollipops, but I'm not making it so my students aren't all working hard but still sinking either. My underlying assumption is that effort is also going to fall into a normal distribution, along with intelligence. As such, if too many people are getting A's, it means that the A's are coming too easily.

So, as I was evaluating the students' progress thus far, I found myself thinking, "Egads! I've made these classes too easy." And I know I'm basing this thought entirely on the grades. Not "enough" are failing or doing poorly. Surely, if the distribution of student talent and intelligence is normal, then my grade distribution should be as well, right? Well, maybe. But maybe not.

I have some longitudinal "data" on at least one of these courses. This is the third time I've taught Intro (minor modifications each time), but it's the first time the grade distribution hasn't come out closer to normal. So I know the curriculum isn't "too easy" in and of itself. What's changed?

Well, I'm at a new school this semester. What can we infer from this? Are the students at the new school just smarter? Probably not. They're both public, state schools. Do the students here work harder? Maybe. Maybe they do the assigned readings, whereas I know the students at the last school usually didn't. Maybe my teaching skills have grown by such leaps and bounds since the last time I taught this class over a year ago that the students are just learning so much better! But, nice as that thought is, I honestly don't think that's it.

So what are some other plausible explanations? And do I adjust the course accordingly? Make it harder, so it's not so easy for students to get an A? I'm thinking I should, but not this semester. I've already established a baseline here, and I don't want to shake things up too much halfway through.