Exercise (preferably attempted by participants before the lesson):
Another variation on an old classic. Split the group into triads, and each group is given a bunch of words in a hat (a box may also be used, or a hollowed out rock of some sort). The words, preferably, are about half-way "up" the abstraction lattice; "red" is good, "Steve Irwin" and "Concepts" are not.
Each person in a triad rotates between three roles: guesser, hinter, or observer. The hinter has to get the guesser to say the word within a short time limit (30s? a minute?) without saying the word herself, without saying words that rhyme with the word, etc. The observer writes down all of the hints and guesses, in order, (the observer can be replaced by an audio recorder of some sort, if resources are available) and is instructed to try to figure out the pattern of what sorts of hints lead to the best guesses, and ultimately correct answers.
After each participant plays each role 3-6 times, have the groups meet and discuss what the best strategy was on the part of the hinter. Hopefully they will arrive at something like the lattice strategy without being hinted of it beforehand.
Note: There are bound to be plenty of tricksy ways of imparting the word without saying it but also without shooting up or down the lattice, like rhyming it. I cannot possibly list all of them, but playing this exercise out a few times should reveal enough of those clever work-arounds to ban them.