You can penalize students' incorrect answers with negative points. This feature is most often used in multiple choice tests to discourage guessing. You can enable the negative points option during question creation or when editing a question.
Negative points for incorrect answers is available for the following question types:
For example, if a multiple choice question awards 5 points for a correct answer and 0 points for skipping it, you can set -20% (or -1 point) for each of the incorrect answers. Valid negative point percentage values for a question are -100.0 to -0.0.
You cannot use this for pools or surveys.
If you need to remove negative points, you can only do so on each question individually.
Use the following steps to enable the negative points option and use it for individual questions.
Enable Negative Points on the Test
On the Control Panel, expand the Course Tools section.
Select Tests, Surveys, and Pools.
On the Tests, Surveys, and Pools page, select Tests.
On the Tests page, click the action link to the right of a test's title to access the contextual menu.
On the Test Canvas, click on Question Settings in the upper right hand corner of the frame.
Under number 4, ensure the check box for Specify negative points options for answers is selected.
In order to make negative points visible, you need to ensure Specify partial credit options for answers is also selected.
Click Submit to save the settings change.
Enable Negative Points for a Question
For each question you want to have negative grading, select the check boxes for Allow Partial Credit and Allow Negative Scores for Incorrect Answers.
For each incorrect answer, type a negative percentage in the Partial Credit % box.
With Negative Grading Enabled, you can enter a percentage between -100.0% and 100.0% into the Partial Credit box.