Reading for January 8

(Article 1) By using subject means rather than individual observations, are we losing important information? For instance, an anomalous case may disappear when only considering the mean, but this case may still be scientifically relevant (if not statistically relevant).

(Article 3) The paper claims that the blood pressure of an extreme group will surely decrease without treatment due to regression toward the mean. Is this statement dependent on biological variation in blood pressure? In other words, does it assume that subjects with extreme measurements typically have lower blood pressure than what was recorded?

(Article 4) This paper seems to be fairly one-sided. I wonder if there are advantages to using change or follow-up scores versus ANCOVA that the author fails to mention. For example, change scores may be easier to interpret and require fewer conditions than ANCOVA. I also wonder which method is more common in practice.