This post had been a long time coming, where I discuss grading media with a score, and specifically how I do it, particularly with regards to anime on this blog, but it’s transferable.
Now, each reviewer and sometimes each review is different, there are multiple grading systems: You can have each show start at 10, and then deduct points for anything that bothers you, and then you might not know what you liked, but you certainly know what stopped a show from being perfect.
You can do the opposite, start from 0 and add points for each thing the show does well. Such reviews often have categories, such as “Production”, “Plot”, etc. and either average all of them or you can earn up to a certain mark in each score and then you add up.
I don’t engage in these forms of scoring. I also want to stress again, that the number is the least important and least interesting part of any review, especially mine – I mean, I use so many words to describe my thoughts regarding the media, so that the final few digits shouldn’t carry so much weight.
I also don’t rate all shows using the same measuring system – I have the “How much do I enjoy the show?” meter, and “How good do I think the show is?” meter (often has a lot to do with aesthetics, but not visual only, but also how I judge the plot to be). I can really love a show that isn’t that good and give it a good score, or not that good of a score. I can think a show is “objectively great” (those are scare-quotes) but not connect to it emotionally, and it might get a good grade or an average one. There’s a sort of averaging going on here, but it’s weighted by how much weight I give to the meter with regards to the particular show – that is, whether how much I like it outweighs how not-great it is or vice versa.