I prepared a simulation to check the workshop for future use.
In the simulation there are 22 participants, 19 of them submitted the homework.
I selected 5 reviews per homework, but deliberately I simulated only 14 participants submitted all the reviews and the 15th submitted only 2 reviews out of 5. The partial grades are made by "number of errors" method, with 3 questions, so 3 "yes" are equal to 100.
In the Grading evaluation phase Moodle calculates the grades only on the basis of the submitted reviews, introducing errors. For example, participant Toni Due has a partial grade of 66, given by Giuseppe Antonini, so the final grade is 17, calculated on 4 reviews because Toni Tre's reviews is missing. But in this way the final grade is enhanced by mistake, because if Toni Tre's reviews was 0, the final grade was 13.
Is there a way to make a fair grading if some participant lacks of assessing some other?