When given a 5-star choice “very bad/bad/ok-ish/good/very good”, I rarely pick one of the extremes.
I suspect there are others who rarely click “bad” or “good”.
Because of that, I think you first need to train a model on scaling each user’s judgments to a common unit. That likely won’t work well for users that you have little data on.
So, it’s quite possible that a ML model trained on a 3-way choice “very bad or bad/OK-ish/good or very good” won’t do much worse than on given the full 5-way choice.
I think it also is likely that users will be less likely to click on a question the more choices you give them (that certainly is the case if the number of choices gets very high as in having to separately rate a movie’s acting, scenery, plot, etc)
Combined, that may mean given users less choice leads to better recommendations.
I’m sure Netflix has looked at their data well and knows more about that, though.
I apply my own meaning to the 5-star rating, and find it to work really well:
1 = The movie was so bad I didn't/couldn't finish watching it.
2 = I watched it all, but didn't enjoy it and wouldn't recommend it to anyone.
3 = The movie was worth watching once, but I have no interest in watching it again.
4 = I enjoyed it, and would enjoy watching it again if it came up. I'd recommend it.
5 = a great movie -- I could enjoy watching it many times, and highly recommend it.
I suspect there are others who rarely click “bad” or “good”.
Because of that, I think you first need to train a model on scaling each user’s judgments to a common unit. That likely won’t work well for users that you have little data on.
So, it’s quite possible that a ML model trained on a 3-way choice “very bad or bad/OK-ish/good or very good” won’t do much worse than on given the full 5-way choice.
I think it also is likely that users will be less likely to click on a question the more choices you give them (that certainly is the case if the number of choices gets very high as in having to separately rate a movie’s acting, scenery, plot, etc)
Combined, that may mean given users less choice leads to better recommendations.
I’m sure Netflix has looked at their data well and knows more about that, though.