Yes. With these, we may never know whether it was a “club” effect (finding quiz too much effort, trolls go bother someone else) or a true deterrent (surprised by quiz, would-be troll says something worthwhile).

The 2002 post is alluring and even clever but it does not put us closer to a solution to comment spam.

No, it’s more about what doesn’t work.

How about a mixed method approach where the user is asked to pick the x number word, not of the post but of a random paragraph that is emailed to the user. Annoying? Perhaps, but it doesn’t necesitate a link in an email.

Questions like this are easy for spammers to process. There are plugins that do math captchas — but that’s easily beatable. Clicking e-mail links or responding to information sent in an e-mail is a hurdle, but it’s beatable in an afternoon of coding.

If this is the only downside, it’s all up for me. I enjoy writing the quiz. Even if it only takes a few seconds, the process forces me to consider my audience and sometimes results in last-minute edits.

Say, I don’t know if I asked you, but have you noticed any effect on the number of off-topic or stupid comments? If it reduces those (as well as comment spam), it’d definitely be worth it for me.

How about a mixed method approach where the user is asked to pick the x number word, not of the post but of a random paragraph that is emailed to the user. Annoying? Perhaps, but it doesn’t necesitate a link in an email.

“…independent studies alleged that Lojack actually deterred crime, presumably by making it much more likely that criminals (and entire criminal organizations) would be discovered after the fact.”

Comment spam is not like car theft. Chop shops have scant in common with spam operations. Notably, authorities don’t get excited about taking down spammers. Only those who feel that their property rights are infringed (bloggers, hosts, ISPs) will act. Excepting vigilante justice, Lojack is irrelevant to the problem at hand. The 2002 post is alluring and even clever but it does not put us closer to a solution to comment spam.

sunburntkamel: Quiz has a very weak comparison algorithm: strtolower everything. In crafting a question, I try to minimize ambiguity in the answer by keeping it simple or giving it away in the post. The author must consider the audience.

Mark Nichols: think about that long enough and you’ll invent CAPTCHA all over again.

beau: that is a “club” and not a hard one to defeat with a script.

After long consideration, I concluded that an accurate predictor for my evaluation of a comment is a red herring.

Have the plugin store the required word as postmeta (and make sure it’s updated if the post is edited!) and you’re done, no?

The call-back was to ensure that the call wasn’t a prank (we were in a college town). If the number the caller had given didn’t pan out, then we weren’t out a pizza.

I wonder if a commenting system that required an email response from the commenter wouldn’t work. Perhaps with a non-HTML link to respond to, i.e., not something that could be automatically clicked on by a script.

It’s a great idea, but i’m not sure a machine can be trusted to validate a more complex question than “what color is snow”, which even tempts me to answer “yellow”.