Hey there! Troll responses are responses that are invalid, and do not reflect real-world behavior.
For example, if a player says, "Yes, I've purchased an Event pass," but they HAVEN'T actually purchased an Event Pass, it indicates that they aren't answering the survey honestly. That would be a "troll" response.
If a player says, "Yes I've purchased an Event Pass, and I f*cking hate them. They're terrible. Riot you suck." when they HAVE actually purchased an Event Pass, that is NOT a "troll" response, and would therefore be treated as a valid player opinion.
I hope this clears things up :)