captcha

Frank O’Pinion, Radio WKWR’s morning show host, is using the airwaves for a bit of a personal moan:

So I was trying to book flight tickets for later this year on one of those budget airline websites. Everything’s going fine: dates, times, prices – all OK. Then I made the mistake of checking baggage costs. Up pops a captcha. Then I checked credit card costs – another captcha! With all these captchas popping up I completely forgot what I was looking for!

A captcha is…
a) the capitals lock button on a keyboard which can unintentionally be applied, leading to input errors especially of any data including numbers, e.g. dates, prices.

b) a virus, named after the capchur tranquiliser gun, which appears to be friendly but is, in fact, quite deadly.

c) an online challenge-response test designed to decide between humans and computers.

Here is the correct answer.

The term “captcha” was coined in 2000. In order to be certain that online enquiries are being made by a person as opposed to being purely computer-generated, a simple challenge-response test was devised. A common type of CAPTCHA (an acronym based on the word “capture”), which stands for Completely Automated Public Turing test to tell Computers and Humans Apart, requires the user to type letters or digits from a distorted image that appears on the screen. This is a simple exercise which cannot (yet) be performed by automated software.

a) Captchas rely on visual perception, a skill not yet perfected by automated recognition software.
b) More recently, captchas have employed picture as opposed to text recognition.
c) Captchas can be extremely irritating to the user if overused by the host site.