One of the most important aspects to consider when deciding whether to implement extra credit questions is how they are factored into a student's score and overall grade. When an extra credit question is answered correctly, points will be added to the total assessment score. However, nothing will be deducted from the score if answered incorrectly.
When scores for a quiz with extra credit questions are transferred to the course Gradebook, the student score comes across exactly as it is in the Quiz Generator, even if the value is beyond the maximum normal points for that quiz. Any points (or percentage) that goes above the maximum normal points (or 100%) for that quiz is added as a bonus to the calculation of the student's final grade in the course.
Note: If a quiz has extra credit questions, and that quiz is part of a category in the Gradebook, the extra credit points a student receives only apply to the category in which the quiz appears. The extra credit points do not get added in at the end to the overall grade.