Maths correctnessMaths understandingQuestions and remarks
BestNo errors in the report nor the talkThe talk is motivated and contextualized;
statements and definitions are explained and contextualized;
examples are present, relevant and introduced clearly
Questions posed before or during the talk were understood and correctly answered (except exceptionally hard questions) by the submission of the final report
OkayMinor errors in the report (i.e. errors beyond the expected comprehension)Motivations are there, but confused;
examples are lacking or not thoroughly introduced
Questions posed before or during the talk were understood, but no correct answer was provided
Badsignificant mathematical mistakesmotivations are lacking or very confused or even wrongQuestions posed before or during the talk were not understood

I think maths correctness is the least important grading criterion out of the three (this is really based on the assumption that students are not going to make big mistakes; serious mistakes are considered separately and can bring the grade down significantly!), then there is maths understanding and finally questions and remark. The reasoning behind it is that it is easier to avoid making mistakes in the left columns even without a clear understanding than it is in the right columns. Therefore these indicators don’t carry as much weight for me.