How to distinguish a good and conscientious review from a bad one?

Question

Algorithms

There are stories on the site.
There are festivals on the site where the author can leave his story, hoping to get N-th number of reviews for him (minimum 500 characters) and must leave N-th number of reviews at a particular festival.
But our users are unscrupulous and leave replies, write "Nnnnnnnnnnn"-like comments, copy-paste. The authors can mark a good review received or a bad one, moderation reacts to a bad one, but the authors do not like criticism, so a sensible review that criticizes the work can be marked as bad.
How can this problem be solved? How can you tell a good review from a bad one? Maybe some sort of scoring system?
Sincerely, Lieroes

Answer 1

From "Nnnnn" will help check the dictionary and the length of individual words above the critical threshold.
But this does not protect against a random set of words from the dictionary.
On the site itself, try to measure the time spent filling out a review. Too short can mean copy-paste, or a legitimate review written in advance in another program. But several reviews in a row with a short period of time is a spam pattern.
With a large volume of texts, you can try to expand the analysis of the words used and the distances between them - to train on manually verified exactly-reviews and arrays of valid text comments, maybe from another forum where there is no point in spam and cheating and all comments can be considered valid. Then it will be possible to put a new comment on the probability of its spam/reality and ask the moderators to check only the most suspicious of them, as well as a few randomly selected, marked as valid.
Another strange idea: to ask the authors themselves to come up with a few more questions for their story to quickly check whether the critic has read this work at all? Not in the forehead "The main character's name is: Vasya / Tolya / Olya" and not something that is searched for in the text by a search. And abstractly: "This story: combines irony and description / describes a love triangle / is a philosophical essay"

Answer 2

1/3 - author's vote, 2/3 - commentators' vote (total score)
(try to study this, because this is the most basic question about the balance of the system)