[OSM-talk] ReMAPTCHA Demo BETA 0.2 online! (Was: Hate captchas!!!!)

moltonel 3x Combo moltonel at gmail.com
Sat Mar 29 13:21:46 UTC 2014

On 28/03/2014, Stefan Keller <sfkeller at gmail.com> wrote:
> The ReMAPTCHA Demo BETA 0.2 finally is ready to be tested:
> http://remaptcha.herokuapp.com/

Great, looks promising :)

> Please note that perfomance is slow (so hover over satellite icon taks
> seconds), and that the data is restricted to Switzerland since that's the
> imagery data I needed (if anyone knows freely accessible aerial/satellite
> imagery of similar quality I'm interested).
> I'm open for hints and enhancement requests (excuse me that I can't answer
> then all).

I'm worried about bots still having a very high chance of sucess. With
two fairly-legible words in the image and a chalenge asking me to
write either one of the words or both, a bot still has 33% chance of
success if answering randomly, wich is high enough that bot authors
won't even bother trying to smartly interpret the map.

The most direct way to reduce those odds is to put many words in the
picture. But that'll quickly get messy and as annoying as traditional
captchas. How about getting rid of words alltogether ?

First of all, display only the satellite imagery, because the map
rendering is too parseable for computers, and not really necessary for
humans. Then ask the user to click on specific areas of the image,
using your knowledge of the underlying map data. Some challenge
examples :
 * Click on the car park if you can reach it from the motorway,
otherwise click the big building.
* Click on the playground, then the fountain, then the lake
* Click on the road that leads to the football pitch
* Click on one of the park entrances

More information about the talk mailing list