I am doing a business site for a web company, and was wondering if Captcha has become so well-known, that it no longer needs an explanation ?
Right now there is only a input box, the captcha image and a headline saying "Captcha". But should we put in an explanation, just to be safe ?
The client is against an explanation, since the design is very clean.
But how many people do you believe are familiar with Captchas now-a-days? (both with and without our target audience taken in perspective.)
I have found that most web literate users are familiar with the concept of a CAPTCHA, but most are not familiar with the term "CAPTCHA". Even my parents (who are not web savvy) understand the idea of "enter these characters to prove you're a human" -- however, they wouldn't understand the headline. I would recommend something more straightforward: "Please enter the following characters".
As an aside, please be absolutely sure you need a CAPTCHA at all! There's a lot of research which proves that they dramatically impact both the ease of use and conversion rates. See the following:
Be sure to see this related question on StackOverflow.
Another concern with a CAPTCHA is that you need to remember accessibility. If you have no text, you may not let blind users know that there is even a CAPTCA available.
"Try" and audio CAPTCHA if you can't see the letters?
Also, someone mentioned above that you can use the text "Are you human". I've seen this used before but I think when you are concerned with less savvy recognizing function, this probably takes away from usability and is more of a cool factor. Stick with the standard copy that is time tested and mother approved.
Post an image. There's always a clean way to add things, even when they require instructions.
Unless you are using an alternative to the regular CAPTCHA, it should be pretty much understood. Keep this in mind:
Don't add simplicity, remove complexity.
In this case, I think adding simplicity would be trying to give direction on something people already know.
