Comment Spam Prevention Through Interrogation

By Deane Barker on May 23, 2005

Sky Captain and the World of Tomorrow: I posted on this entry over at Joseph’s Scott’s blog, and he has an interesting comment spam prevention tool going on.

The comment form asks you a question — in my case, “What color is an orange?” I tried to be cute and put “Um, orange?,” but it doesn’t have much of a sense of humor. Unless you write, simply, “orange,” you get no joy in posting your comment.

Interesting concept. When the page reloaded, the question was the same, so bots could predict it. But (1) no bot is going to custom program something for one site, and (2) he can just change the question to something like “When was the War of 1812?”

I think he’s got a winner here. Is it any better than a captcha? I don’t know. Easier, though.

What Links Here


  1. I’m using WP GateKeeper, a plugin for WordPress. The orange question is the default and you can add your own questions and answers so that it doesn’t always display the same one.

    If I were a bot writer I’d look at trying every word that appeared in the question, which would defeat both the orange question and your 1812 question. Ideally you’d want to ask a question with and answer that doesn’t appear in the question. Math questions might be a possibility (what is one plus one?), but bots would likely be able to learn how to defeat that also.

    So far though the orange question has done the trick. I’m not sure how long that will last, but I’m going ride it for all it’s worth.

  2. Why not use a combination of the question and an image (like CAPTCHA). I don’t use Word Press or PHP (anymore) but .NET has new graphics features that will make this pretty easy to do.

  3. Everything old is new again. I remember back in the dial-up BBS days, the main system in my town that was devoted to CP/M used a similar system to keep kids out. The very first prompt when you connected would ask you a question to which the answer was obvious to any CP/M user, but which would baffle anyone else.

  4. Craig,

    You ran into some downtime on my site. It was back online after awhile, so try it again if you want to check on the comment question.


Comments are closed. If you have something you really want to say, tweet @gadgetopia.