[dotancohen]

  > As we also measure the decision time,

From very much experience in designing and running online interactions, including polls, I can tell you with authority that you cannot trust the decision time of answers online. You don't know that they user didn't look at a quick text message on his phone, or adjust the music volume, or go to the bathroom, or take a call, or had a network issue, or your images didn't load quickly, or the dog didn't bark suspiciously, or a loud C-130 just flew overhead, or any other of a million things. I highly suggest disregarding that feature.

[pinko]

Isn't that just noise? It's possible to extract useful signals from extremely noisy data if you understand the statistics.