Validating number questions

You can validate numerical input from respondents using a **Validation Message** question type. This is helpful when you want to enforce a sum total for numerical values such as enforcing that percentage values add up to 100.

For more information, see Validation Message Question.

- First, add a question where users will input numbers such as a Matrix Number Boxes question (Matrix Number Boxes Question):

To validate that the numbers entered in Input 1 and Input 2 add up to 100, you will need to add a Validation message after this Matrix Number Boxes question.

- After building your Matrix question, right-click the last row (Input 2 question) on the
**Edit**tab, and click**Insert After**.

- Click
**Validation Message**from the Question Gallery.

- In the Validation Message editor, enter the message that will appear if the sum total of question 1 is
*not*100 - such as*The sum total in the last question does not add up to 100. Please go back and correct your answer*.

- Click
**Ask if**. The**Ask if**page displays.

- On the
**Ask if**page, choose**Other**from the drop-down menu, and click**OK**. The**Ask if Conditional**page displays.

On the**Ask if Conditional**page you will enter a formula to validate that the numbers entered in Input 1 and Input 2 of question 1 add up to 100. The formula will state that if Input 1 and Input 2*do not*equal 100 a validation message should display.

The formula will need to reference Input 1 and Input 2 from question 1. You can reference question fields using Vista syntax as described in Using Piping and Advanced Ask if Logic. In our example, you will reference Input 1 with [Q1a] and Input 2 with [Q1b] and enforce the "do not equal" rule with the operator !=. The formula to validate question 1 is: [Q1a]+[Q1b]!=100.

- Enter the formula [Q1a]+[Q1b]!=100 in the
**Ask if Conditional**page text area, and click**OK**.

- On the
**Validation Message**page, the formula is displayed next to the**Ask if**button.

- Click
**OK**to return to the Edit tab.

- To test the formula, click
**Test Logic**from the left-hand menu.

- In question 1, enter numbers that do not add up to 100:

- Click
**Next**.

The validation message displays and the user must click the**Back**button to return to question 1.

**See also:**

Formulas

How do I make questions conditional?