How can concepts like comprehension, abstraction, meaningful experience (among others) be adequately accounted for in an experiemnt-based research so that the results given gain external validity? In other words do we have to measure these concepts (or similar ones) someway before attempting to draw general conclusions out of the results given by our experiments?
Conversely, do we simply accept these concepts as unavoidably cumbersome and focus instead on obtaining results under the most controlled environments valid only within said environments (i.e. the example of the NCLB research in the Lodico article)? And then construct upon these findings to find (or avoid) the ideal envioronment to conduct art (or any) education?