Acronym

It was looking like spam was going to win the battle, but, risking the ire of the nuisance gods, it appears that we've come out on top. At least for now. For those of you with blogs or considering them, I asked John Stone from our service provider to explain what we've done to combat the comment spam:

"Over the last few months, the delivery of spam and junk posts through Web based forms has risen significantly. Comment forms like those at the bottom of ASAE's blog site can easily receive hundreds of junk posts a day. While it may be simple to delete each post, it's a time-consuming process and ultimately degrades the quality and value of the site.

To reduce automated posts, many sites have turned to reverse Turing tests, more commonly known as CAPTCHA. CAPTCHA is simply an acronym for “Completely Automated Public Turing test to tell Computers and Humans Apart,” and is trademarked by Carnegie Mellon University.

A CAPTCHA reduces automated posts by asking a question that only a human would be able to answer. The most popular test challenges a user to enter obscured text embedded within an image. You'll notice these graphics on many reservation system sites, online stores, and at the bottom of ASAE's own comment form.

While it is relatively easy for a person with good eyesight to see and enter 9059, an automated computer program or “bot”, is essentially blind to anything but the publicly available HTML source. A good CAPTCHA program, will insure that there is no textual reference to the image's content, making it easy for us to identify the real posts.

While CAPTCHA does a great job blocking automated computer software, it isn't perfect. Common problems with a visual CAPTCHA are that it can make it very difficult for those with visual disabilities to participate and it's only a matter of time before automated software includes optical character recognition that does it's best to decipher your obscured image.

Deciding whether your site should use a CAPTCHA is probably more difficult than actually implementing one. Many Web based applications already include plug-ins that simply need to be enabled; many others will make such tests standard features in their next releases. For custom sites, CAPTCHA is still an option and can be installed within a few hours once a few key elements are configured.