Here is a trick I used to create a situation where the true causal effect is known in the presence of real, not simulated, confounding. When computing the total score (whole) from individual item scores (part), we know the causal effect of each item score on the total score.
Apr 24, 2019 • 7 tweets • 5 min read
@yudapearl@nagpalchirag Indeed, I have one very strange example where identifiability seems easier to see with PO. First, let me be clear that I am not making up the causal question. It is a real research problem that has baffled educational measurement researchers since the 1920s.
@yudapearl@nagpalchirag While taking multiple-choice exams, examinees may or may not change their initial answers. The decision is made by their ability, anxiety, and many other unknown factors, which also affect the final score. People have wondered whether answer changing is beneficial or harmful.
