Discussion grades

A student expressed confusion when she saw her points for a discussion topic were 10/10 but I said that there could be 20 points per topic with a maximum of 80 for all discussion (8 topcis total). I replied:

Each of the 8 unit discussions is worth 10 points for a total of 80. I do not want to devalue the other assignments that make up the class grade, so I leave at 80 the maximum points that can be earned through discussion. However, I recognize that some students will find certain topics more interesting and I also want to encourage communication among students, so I award points for quality responses to what our classmates write. These are extra credit within that discussion topic with a maximum of 10 extra credit points, so the score for an individual topic can be up to 20/10. Therefore it is possible to earn all 80 of the discussion points possible in just 4 discussion topics.