"assign ratings" is correct and usable in written English.
You can use this phrase when you are referring to assigning numerical values or rankings to something. For example, "The company assigned ratings to its products based on customer feedback."
The literature on this topic has developed especially in connection with Basel II, which allows banks to set up an internal rating system, that is, a system to assign ratings to the obligors and to quantify the associate probabilities of default.
when Iranian students rate their own essays, they are not likely to assign ratings that are lower than those that they would assign to their peers' essays.
Esfandiari and Myford (2013) stated that when Iranian students rate their own essays, they are not likely to assign ratings that are lower than those that they would assign to their peers' essays.
"RBC understood the mathematical models used by S.& P. to assign ratings on synthetic C.D.O.'s," the firm maintained.
The S.E.C. must now study whether to create an independent body that will randomly assign ratings to different agencies.
To find out how influential you are, there are sites that assign ratings to people, like Klout and PeerIndex.
This site tracks the records of professional stock pickers and pundits, assigning ratings based on performance.
Another form of adaptive Web site assigns ratings not to submissions themselves but to members' comments about the submissions.
The Entertainment Software Rating Board, an industry organization, assigns ratings to video games in a way that is not unlike the Motion Picture Association of America's system for rating movies.
Two services that rate the creditworthiness of companies -- Moody's Investors Service and Standard & Poor's -- have for the first time assigned ratings to the Publicis Groupe, Paris.
And if they are medically discharged, the system assigns ratings to their disabilities that determine what kinds of benefits they will receive as veterans.
