I had been practicing my serve for 30 minutes (my partner was a no-show) when a guy asked "Do you want to play some?"
It only took two ripped top-spin forehands to see that he was better than me. I told myself "It's a learning experience." It was indeed an education, but not so much about tennis. Double-faults into the bottom of the net; shanked forehands; back-hands sailing to the back fence.
Maybe it was the different court surface. Maybe it was the poor lighting. Maybe. More likely, though, it was me tensing up when confronted by a better player.
I told myself to relax. I played worse. "Just watch the ball," I said, then pulled my head up. "Have fun" was followed by kicking my racket.
Test anxiety. I am a reasonably good tennis player, but that other guy sure didn't see evidence. I failed the test.
How many of my students know more math than they demonstrate on a test? I suspect they are not much helped by my exhortations to "relax," or "just do your best."
Our state forces students to re-take classes if they fail an End-of-Course exam, even if the teacher knows the child knows the material. Our system requires a final exam to count for 25% of a grade. We say the student has to "demonstrate mastery," then often define such mastery using a bubble-sheet.
If I believe my tennis skills should be measured by more than one match, then surely we should use a variety of means to assess our students. We need to move away from "passing the test" and towards "doing the work."