When i search i found ICO projects with very good rating, this rating posted buy ICO rating websites, how this rating works, websites did not mention about the factors use to rate this projects.
Choosing an ICO project based on ratings and making it into consideration is not wrong, but you need to be careful because some sites give fake ratings. So in my opinion, don't just judge an ICO project based on its rating, you can start by looking at how the team and the products they bring, to avoid or minimize the risk of getting a scam, the activeness of the team behind it is something to consider.