Detecting bots with Javascript for better A/B testing results

With regards to GWO, see http://www.bingocardcreator.com/abingo/compare . Google doesn't use GWO on any page of importance and neither should you.

On the general topic of doing A/B testing server side (with Rails or what have you) versus doing it client side in Javascript:

1) Doing it in Javascript sacrifices one-line A/B tests, and that is a cost I'm totally unwilling to put up with because it means I will be too lazy to actually do A/B tests. (Take a look at the framework posted yesterday and what they have to do two swap two divs. That is fairly representative. Note that it gets harder, fast, if you start doing anything the least bit complicated.)

2) Javascript is not your friend for load times. A/Bingo and similarly optimized server-side frameworks are, essentially, free in terms of user-perceptible performance.

You need to be fairly technical to disable javascript. That or there's an administrator doing that for you (like in some company).

So, besides companies which restrict javascript (very rare?) there's only those using noscript (very rare?).

That depends on what you mean by detecting. If you mean recording the fact in a log file then it's definitely possible. You could just log everyone as a bot by default and then remove them from the log if the ajax request comes in.

Assume user #1234 requests a page with an A/B test on it. We hand them the page and a Javascript challenge, and mark them as a bot. If user #1234 successfully passes the Javascript challenge, which if it happens will almost certainly happen within the next few hundred milliseconds, we revise our opinion about their character. Anybody who fails to convince us remains flagged as a bot.