Most people are familiar with the multistable image: what you look at remains the same but your perception of it changes. Some people have trouble "seeing" the alternative image, until it is pointed out to them; thereafter, their vision will switch between the two images.
For preK-12 teachers, the NWSA Convention was an experience in multistability. Nine sessions listed in the program dealt specifically with curriculum, methods, and approaches at the precollege level; and seven were actually held. Most were scheduled when public school teachers were free to attend. A few drew audiences of nearly twenty people. Yet of the fifteen people attending caucus sessions, only five were actually teachers of preK-12 students.