Concepts, ideas, opinions, feelings, and other intangible entities are often labeled as “insubstantial phenomena.” Select one of the following 3 phenomena that would be considered insubstantial, and explain two different ways — one qualitative and one quantitative — that you might measure it: a) the closeness of undergraduates’ social network friends; b) the “campus climate” at your university; c) “irrational exuberance” about the stock market.