How to validate data in excel.

Data Validation - worksheet cells can be adjusted so that only certain values can be entered.

purpose: Controlling how data is entered decreases errors and makes a worksheet more reliable.

steps:

1. Select one or more cells to validate.

2. On the Data menu, click Validation, and then click the Settings tab.

3. To specify the type of validation that you want, do one of the following:
    a. Allow values from a list
    b. Allow a whole number within limits
    c. Allow a date within a time
    d. Allow Date
    e. Text Length
    f. custom


You will see the result here:

So as you observe that once you place cursor to the active cell , a drowpdown arrow will appear and display only a yes or no data.