I think I have it.
Quite by chance, I wound up covering tonight’s study hall for ninth graders — the students I teach — and I talked to about a third of my students. It turns out, a lot of them plagiarized (or at least said that they plagiarized) because they didn’t know how to extract economic data from our textbook, or they didn’t know what that economic data meant, or they didn’t know how to encapsulate it in a sentence or paragraph.
That’s about three different kinds of failure there, and had I designed a better formative assessment I would have caught all three. There’s all sorts of economic data in the textbook, but it’s deeply coded — knowing that Alexander enslaved and sold the inhabitants of Thebes is one thing; knowing to look up the approximate price of slaves on Wikipedia is another; and knowing how to compare that data with the next piece of information is another.
I’ve tried to answer these three types of difficulties in the slideshow above, which is now embedded in the class wiki, and will be part of tomorrow’s class, and is now part of my class’s permanent archive.
How’d I do?