Trip Advisor states the following regarding their star ratings:
"A summary score based on quality, quantity and age of traveler ratings."
It does not state anything on how they base the quality but assume it must have something to do with the helpful question. As reviews age, or if the poster only has one or two posts, they loose creditablity. So, if a guest just signs up just to post a review on your place, and never does another, over time the review looses creditability.
They are really going all out now to qualify the review too. I just received a call from a past guest from England. He said, well I posted a review on TA and it JUST made it on the site. He said that he received 2 emails to confirm that he was a 'real' poster and had really stayed at our B&B.
What bothers me is that it takes a real dedicated guest to go through all the trouble to post on TA, while this makes the site more reliable it also will detour some from going through all this. My worry is that the most dedicated posters may turn out to be those PITA's that just left......