You'd expect a software system to have a manual, wouldn't you? That's how our Lertap 5 documentation started. You ought to make it a point to read at least a bit of it -- it's more than a manual, more than a how-to, and, perhaps best of all, the author frequently had his funny bone active when typing. It's got real examples, and in numerous spots serves as a comprehensive technical reference. You can get to it via this link.
After the system was initially released in the year 2001 (officially), a series of technical documents, referred to as "erudite epistles" began to emerge. These explain more about using Lertap 5 in practical contexts.
Lertap 5 has continued to grow; many enhancements have been added since its initial release. Instead of updating the manual with every enhancement, a dedicated website called "Lelp" (for Lertap help) was brought online to cover changes and provide related reference material. It's updated fairly often, and it's all yours in a variety of formats. Don't miss it, see it by clicking here.
In 2011 a special website was developed with numerous sample datasets. Almost all of these are from real-life applications of Lertap 5, and all but one may be downloaded as an Excel workbook, ready for practice, experimentation, and class research projects. They've become very popular.
Another dedicated website came online in 2013 to demonstrate a variety of Lertap 5 and Excel "tips and tricks" in the context of an authentic national assessment of science achievement.