A students might make a (common) mistake in finding the answer to the task. AlgebraKiT has a number of common mathematical mistakes included in the knowledge set of the student, in which automated feedback is given on the possible mistake the student made. However, AlgebraKiT might not recognise all mathematical errors. Furthermore, there are also exist context-specific mistakes where a student makes mistakes in selecting the wrong context value for the task calculation.

Click on the Action button on the bottom left of the interaction field and select the Add incorrect answer option. An incorrect answer field appears below the step task(s).

Click on the new field. A new definition field opens.

Select the task of the incorrect answer and enter the expression. The specific feedback should be entered in the text-editor on the right of the field.

Removing an incorrect answer can be done by clicking on the bin on the top right side of the field. Adding another incorrect answer is done by clicking on the + icon on the top right side or by selecting the Add incorrect answer option in the actions menu once more.

Note: this field is intended to define incorrect answers for the step you are adding the incorrect answer to. You also have the concept of defining an incorrect step on step level, which is intended for strategic errors, rather than task errors.

##### Example

Let’s look at the question where the student needs to find the square root of $-4$. This is a trick question, as they have not learned complex numbers yet, so the answer is $no solution$. However, some students consider $\sqrt{-2}$ as a valid answer. In this case, we want to give feedback that they can verify their answer.

We have created an algebra interaction with $\sqrt{-4}$ as task, together with an incorrect answer $-2$:

Now try it yourself by entering $-2$ in the interactive exercise below.