By example.
You show a video of the first couple moves of a past performance.
A bunch of trained people play technical specialist or judge. They explain what points they are awarding, for one or two moves. Each explains how they arrived at that number, which number goes on the screen. A formula appears on the screen showing how the points are awarded for that move.
Maybe you do the same thing for step/choreography sequences.
Examples and role playing are easier to relate to than abstract concepts.
Have a little fun with it: add a little cosplay among the pretend judges.
Queen of Hearts ("Off with his head!"), The Grim Reaper ("I always get my man"), The Angel of Music (Johnny Wier commentates for NBC), Prima Balerina, etc.