Conditional Formula for Unique Issues

[kemmek]

I have a complicated question that I was hoping someone could help me out with. I have four columns in a spreadsheet- “Issue Topic,” “School,” “Start Date,” and “End Date.” I would like to set up a formula that calculates the time elapsed for unique issues (End Date- Start Date). The way I am defining non-unique issues is if the first three columns are the same as the first three in a previous row. I haven’t been able to figure out how to write a formula that would lookup unique entries and calculate the time elapsed for those entries. Is this possible? Does anyone have any suggestions? Would I be able to at least calculate an average time elapsed for unique issues? Thank you in advance for any help you can provide.

[GuruWannaB]

Can you provide an example sheet...with an example of the output you would like to see?

[Mallycat]

A pivot table will do what you want. I have put a sample here for you

[kemmek]

Wow- thanks so much. I didn’t even know that something like pivot tables existed, but that’s really helpful!