It can be easy to forget that Google I/O is a developer conference, so there are plenty of dev-focused announcements that don't get keynote attention. Most of that is of little consequence to the average user, but you might notice the upcoming change to Play Store ratings. Starting later this summer, Google will recalculate review scores to give more weight to recent reviews.
Throughout the history of Google Play (even back when it was the Android Market), an app's overall review score has treated all individual ratings equally. Google says developers have been asking for the rating to focus more on recent reviews, so that's what it's doing. Google doesn't say exactly how it's changing the weighting, but developers can log into the dev console to preview their new score now.
This change will make it harder for apps to skate by on the goodwill of yesteryear after a bad update, and it will help developers turn around a bad score by addressing user concerns. As part of this change, Google will also highlight reviews to which it thinks developers should reply. Replying to negative reviews causes users to add an average of 0.7 stars to their reviews, says Google. The revamped review scores will be public on the Play Store in August.
- Android Developers