Duplicate entries may be valid -- but when they aren't, they can derail your summaries and totals. Use Excel's Validation feature to reject duplicate entries.

Excel's data validation feature offers an efficient way to perform a variety of tasks. This collection of techniques demonstrates several handy ways to ...

A common use of data validation is to create a drop-down list. Use it to restrict the type of data that users enter into an Excel cell.

In many cases, you want people to enter a valid date, and no other type of information, when they're putting data into a cell in Microsoft Excel.

Learn how to create a drop-down list using Data Validation in Excel. Data Validation limits the type of data that can be entered into a cell.

Automated Data Entry in Excel. One way businesses can save time and money is using Excel spreadsheets as data tables in which to store customer information, inventory details or other important data.