Lertap, the Laboratory of Educational Research Test Analysis Package, is a computer program used to process and analyze results from tests and surveys. It has gone through several generations since its birth in the early 1970s. The fifth generation of Lertap, known as Lertap 5, was first released in 2001, and is designed to work as an application running within Microsoft's Excel program.
This document provides some idea of what Lertap 5 does, and how to go about getting it to do what it does. If you're new to Lertap 5, you might find other resources to have a more introductory flavor.
For a quick but comprehensive look at Lertap 5, try these web-based PowerPoint slides, or, if you prefer, browse the pdf version of the same slides. (Note: these slides show screen shots from Excel 2010 -- Excel 2007 looks much the same, as does Excel 2013, as does Excel 2016.)
And yes, if that's not enough, there's even more: have a gander at our sample datasets website. It's a jim-dandy source for quickly getting an idea of what Lertap 5 does, and it even has some samples which may be downloaded for test drives on your computer.