@Arizona Hot: That mark-sensed exam response document took me back a bit. The clock track on the LHS where it says "Read in this direction" looks very much like the system I used to program for using a machine scanner code macro language. Pity the image doesn't show the whole document. From memory, I think the machine we used was a Westinghouse brand of mark-reading scanner. It ran the program logic in real time across every sheet as it was passing under the read heads, and though it was a very high-speed scanner (I forget how many documents per second it scanned) it could reroute the forward path of each document in its outgoing path, depending on the data that it had just scanned and the logic applied.
I guess the technology is still useful - that image is dated 2010. It was ideally suited to mass survey data collection.