By Stephen L. Nelson, E. C. Nelson

Cross-tabulations in Excel are important, powerful tools. Here’s a quick example: Assume that in some future century that you’re the plenipotentiary of the Freedonian Confederation and in charge of security for a distant galaxy. (Rough directions? Head toward Alpha Centauri for about 50 million light years and then hang a left. It’ll be the second galaxy on your right.)

Unfortunately, in recent weeks, you’re increasingly concerned about military conflicts with the other major political-military organizations in your corner of the universe. Accordingly, assume for a moment that a list maintained by the Confederation tracks space trooper movements in your galaxy. Assume that the list stores the following information: troop movement data, enemy name, and type of troop spaceships involved. Also assume that it’s your job to maintain this list and use it for analysis that you then report to appropriate parties.

With this sort of information, you could create cross-tabulations that show the following information:

  • Enemy activity over time: One interesting cross-tabulation is to look at the troop movements by specific enemy by month over a two- or five-year period of time. You might see that some enemies were gearing up their activity or that other enemies were tamping down their activity. All this information would presumably be useful to you while you assess security threats and brief Freedonian Confederation intelligence officers and diplomats on which enemies are doing what.

  • Troop movements by spaceship type: Another interesting cross-tabulation would be to look at which spaceships your (potential) enemies are using to move troops. This insight might be useful to you to understand both the intent and seriousness of threats. As your long experience with the Uglinites (one of your antagonists) might tell you, for example, if you know that Jabbergloop troop carriers are largely defensive, you might not need to worry about troop movements that use these ships. On the other hand, if you notice a large increase in troop movements via the new photon-turbine fighter-bomber, well, that’s significant.

Pretty powerful stuff, right? With a rich data set stored in an Excel table, cross-tabulations can give you remarkable insights that you would probably otherwise miss. And these cross-tabulations are what pivot tables do.