I've personally never seen any actual scores appear in the rating area on the website.
I tend to assess each project be reading through the bounty, going to the ICO website and checking it out, along with the white paper.
I'll also look to see which team or individual is managing the bounty, as some are much better to deal with than others, but as that is a personal observation, I'm not going to specify any details.
Most times, the ANN thread can also help a lot to know what people are really saying about the project. Although, one would still have to be careful as some are just paid reviews and not just stick to that alone, What I have checked most of the time is to do a proper scrutiny on the team and they will give you the proper answer if it is worth joining or not.
In my opinion, we should not trust anyone. All we need to do is, just investing what we can afford to lose on the events of unwanted things. Nothing else we can do with any types of investments too.