To protect against incorrect data entry, you can use data validation to restrict the type of data that can be entered into a cell. You can choose to allow only certain types of data, such as whole numbers or dates, or you can allow only items from a specified list.
To apply data entry restrictions:
- Select the cells for which to verify data.
- On the Data tab, in the Data Tools group, click the Data Validation command:
- In the Data Validation dialog box:
- On the Settings tab, choose which types of values to allow:
- Note that when you select a type of value to allow, the Data options change accordingly. Set the criteria (between, greater or less than, equal to, Source, etc.) for those values. You can type the criteria or select it by clicking the red arrows to the right of the data entry boxes. If you are only allowing values from a list, you must click the red arrow and select the source:
- If you want to, you can enter a message telling the person entering the data what the restrictions are. They will see this message when selecting any of the cells for which the restriction has been set. To enter this message, select the Input Message tab, make sure that Show input message when cell is selected is checked, and enter the Title and Input message:
- You also have the option of entering an error alert that pops up when invalid data is entered. To enter an error alert, select the Error Alert tab, make sure that Show error alert after invalid data is entered is checked, and enter the Style (choose to stop the person from entering the data, warn them that this data does not meet the criteria, or simply let them know), Title, and Input message:
- Click OK.