For example your rating is 9.64, which is close to 10, so you have almost 5 stars. The first 4 are completely colored in. If you look closely at the fifth star you will notice one of the points is partly uncolored. So that 4.xx stars equate to the 9.64 rating. If your rating was 9, you would have 4.5 stars. If it was 8, there would be 4 stars, etc.  

It is true that the star ratings take effect once you have 5 reviews. A provider with 1 to 4 reviews won't have a star rating yet. Can you link to the profile you said you saw with 15 reviews and no star ratings? If you don't want to expose her profile on the public board, send it to me by PM. I haven't seen a profile like that, but if I see it maybe I can explain it, or maybe it's some glitch in the system. There have been a lot of glitches in the change from the old TER to the new.

-- Modified on 7/7/2017 11:51:14 AM

I believe that in order to have stars you need chemistry and location scores, which only happen on the new TER interface, so it's possible you've gotten recent reviews and haven't been reviewed with the new TER yet as it was only recently they decided to stop offering the "classic" interface.

 
Basically, you need more reviews and it'll happen. Until then don't worry too much, it isn't like you can filter/sort/search by stars yet.  

 
Also, while we're on the subject, it's important to know that chemistry and location are also going into your total score.