I suspect that your friends were simply trying to rationalize their previous behavior or avoid admitting they were wrong. I’ll bet more of them would have been sympathetic to your arguments if they’d been presented before they’d ever taken a test of that type. In fact, I’ll bet a few of them would find your arguments so obvious as to barely be worth mentioning if presented in this context. (E. g. if you’d posed as a brainteaser to your friends: “on a test of this type, do you increase your expected score by guessing or marking don’t know”, I’ll bet some of them would have said “Guess. That’s obvious.”)
According to my interpretation, the only reason your outcome was superior was because you made the discovery early on under your own steam. To measure whether you would be better at admitting you were wrong than your friends, we would have to give you a test where you actually had to admit you were wrong.
Anyway, guessing does increase the variance in your answer. So maybe a more complete argument where you asked your friends how many questions they expected to know and then gave them odds for getting each of “no pass”, “pass”, “honors” and “high honors” using guess and no-guess strategies would have been more effective.
I suspect that your friends were simply trying to rationalize their previous behavior or avoid admitting they were wrong. I’ll bet more of them would have been sympathetic to your arguments if they’d been presented before they’d ever taken a test of that type. In fact, I’ll bet a few of them would find your arguments so obvious as to barely be worth mentioning if presented in this context. (E. g. if you’d posed as a brainteaser to your friends: “on a test of this type, do you increase your expected score by guessing or marking don’t know”, I’ll bet some of them would have said “Guess. That’s obvious.”)
According to my interpretation, the only reason your outcome was superior was because you made the discovery early on under your own steam. To measure whether you would be better at admitting you were wrong than your friends, we would have to give you a test where you actually had to admit you were wrong.
Anyway, guessing does increase the variance in your answer. So maybe a more complete argument where you asked your friends how many questions they expected to know and then gave them odds for getting each of “no pass”, “pass”, “honors” and “high honors” using guess and no-guess strategies would have been more effective.