@Mika330 If hosts are honest in their written reviews, that should give you an indication of whether there is any aspect of being a guest you need to improve on. And you can also ask your host if there is anything you could have done to be a better guest.
Hosts only have 3 individual things to rate guests on- communication, respecting house rules, and cleanliness. So if you are pretty sure you are doing those things well, chances are your ratimgs are fine.
Also realize that star ratings are quite subjective- one host may consider a guest leaving a bit of a mess to be just the cost of doing business and leave 5 stars as long as the place wasn't trashed, another may be quite upset at finding the guest didn't clean up well.
And hosts who don't use Instant Book, like me, can't see guest star ratings, either. All we have to go on are the written reviews. So the guest ratings are only visible to IB hosts, because they need more safeguards since they don't get to communicate with guests before a booking is confirmed.
Even if I used IB, I wouldn't put much stock in star ratings, because as I said, they are so subjective. I would have no way of knowing why a host gave a particular rating unless they mentioned it in the written review.