Advanced Data Validation Techniques in Excel

Data validation is a great way to keep your users informed about possible values in a cell and guide them to select something appropriate. As part of the spreadcheats series, in this post we will discuss 2 advanced data validation techniques that can help you when you are modeling a complex worksheet.

Problem 1: You have 2 lists of possible values and you want a way to switch between both

PS: Many thanks to Alex who proposed this idea and solution through e-mail.
You have a cell where user can enter any value from 2 lists. But you don’t want to overload the in-cell drop down list with tons of values, and rather prefer a simpler approach like this:

Solution: Use an IF() formula in validation criteria

The solution is to use an if() formula to determine which one of the two ranges should be used to validate cell contents.

• Select the cell where you want to have this type of validation
• Go to menu > data > validation
• In the criteria area, select “allow” as “list”
• In the source area, specify a formula like this: =IF($B$7="Full List",Full-list-range,Partial-list-range)

That is all, you now have a data validation list that can change its source based on user preference.

Problem 2 : You would like to change a list’s values based on what is selected in another list

PS: Many thanks to Catherine for asking this question through email
You have a status tracking spreadsheet where each employee enters the status for each of the projects they are working on. They enter the status by first selecting the department and then selecting a project (from that department).
So how do you do this in Excel?

Solution: Use OFFSET and MATCH to determine which range to use

Remember the offset() and match() formulas we discussed in the last spreadcheats?  Assuming the list of projects for each department is in a range B10:C22 with column B having the department name and column C having the project name and the list is sorted on column B, we can use offset() and match() combination along with countif (ahem!) to determine which range to use for project cell drop-down.

• For the department cell, we can use simple list validation with values as “Marketing, Ops, Sales, IT”
• For project cell, go to data validation (menu > data > validation) and specify a formula like this:
  =OFFSET(C9,MATCH($B$6,$B$10:$B$22,0),0,COUNTIF(B10:B22,$B$6),1)
• What is above formula doing? It is fetching a sub-range from the by finding where the first entry for the selected department is, returning x number of rows from that point, where x = no. of projects in that department.

That is all. You now have a list drop-down that changes values based on what is selected in an earlier cell.