The evaluation type eval param rep can be used to evaluate a parametric representation of the solution set of a list of linear equations. It does not have automated feedback itself, but instead, the evaluation type fb param rep can be used to give automated negative feedback on the student’s answer.

**Evaluation type: eval param rep**

The Definition field of this evaluation type should have two arguments, separated by a semicolon (;). The first argument should be a list of the linear equations, and the second should be a list of the coordinates.

When this evaluation type is used in a Solution rule, the evaluation type fb param rep can be used in positive or negative feedback to give automated feedback on the student’s answer.

With the solution Definition above, the student is free to choose the parameters they use. If you don’t want the choice of parameters to be free, you can provide a third argument in the solution Definition which is a list of the parameters that may be used.

Example:

Greek symbols can be inputted by the student using the abc tab on the virtual keyboard:

However, parameters don’t need to be Greek symbols.

**Evaluation type: fb param rep**

This evaluation type can only be used in negative feedback when a solution rule is defined that uses eval param rep. It gives feedback on one of the nine cases specified below.

To select a case, type the number (e.g. `2`

) or the name (e.g. `no_vector`

) in the Definition field. Every case supports automated feedback, and this automated feedback is shown in the examples below. The solution rule that is used for these feedback rules is:

2 (

`no_vector`

)

The student’s answer is not a vector.

3 (

`wrong_length`

)

The vector in the student’s answer has the wrong length.

4 (

`wrong_basevec`

)

The base vector of the student’s answer is not a solution to the equations in the Solution.

5 (

`too_few_parms`

)

The student’s answer has too few parameters.

6 (

`too_many_parms`

)

The student’s answer has too many parameters.

7 (

`wrong_params`

)

When a third argument with allowed parameters is specified in the solution, this rule hits if the wrong parameters are used.

8 (

`non_linear`

)

The student’s answer is non-linear in one of its parameters.

9 (

`wrong_vector`

)

The students’s answer has at least one vector that is not a solution to the equations in the Solution.

10 (

`lin_dep`

)

At least two direction vectors in the student’s answer are linearly dependent.