Lucid Phoenix is a program that plays interactive 'dichotomous' identification keys in a web browser (see http://www.lucidcentral.org/Software/LucidPhoenix.aspx)
When a Phoenix key first loads you will see four panels. Panels can be minimised to make the QUESTIONS panel (top left) larger.
The top-left panel (Questions) holds the questions that need to be addressed at each step (branch point) of the key. The top-right panel (Entities Remaining) holds the entities in the key (i.e. hymenopteran families). On first starting the key, the panels at bottom right (Entities Discarded) and bottom left (History) will be empty, but fill as choices are made in the key.
In the QUESTIONS panel there are two choices of entities. A short statement of important characters is provided that separates the two entities, and images illustrate these characters (with arrows).
A page with definitions and explanatory figures is provided, and further detail on terminology, morphology, etc. can be found in the references in the Further Reading section.