What's the Dependent Variable in Terms of Learning?

"I think one of my main complaints and one of the challenges that the research demonstrates about these is that they're often not necessarily really associated with something meaningful in any way," he says. "We might be assessing what students have memorized, but it's something that they're typically going to forget." He adds: "How do you objectively measure whether a student has had an epiphany? Whether they've changed their mind?"