students were put in groups of four and thrown into the challenge. 2 groups failed to have a standing structure and the others were at 10" and 16". then we watched the video (seen at the link above). groups were shuffled and the challenge was done a second time. After that students did a slightly better job about focusing on the marshmallow from the beginning. More students also started including triangles. I wanted to see more students working directly with the marshmallow from the very beginning and i had to remind them to focus on the marshmallow make sure your structure is solving the problem of the marshmallow weight.
HOWEVER, despite needing those extra reminders (or perhaps because of them) there was a general increase in structure performance. with groups coming in anywhere between 14" and 18". there were far fewer CRISIS moments at the end because the marshmallows were all attached at least 5 minutes after the start and worked with after that.
hopefully this has helped students remember to solve the largest problem first, work from there, to build many iterations of ideas, and to focus on the goal.