i just checked and apparently after the redesign it doesn't appear anymore when you hover the stars. i have changed to storygraph about a year ago.

i just rate it for myself. if it's a revolutionary book at the time of publishing i'll throw in an extra star or two for their contribution to literature even if i hated it

i use what goodreads themselves use

1 star – didn’t like it

2 stars – it was OK

3 stars – liked it

4 stars – really liked it

 5 stars – it was amazing