John Keegan writes: Recent posts from sources where the majority of shared articles aligned “very liberal” (blue, on the left) and “very conservative” (red, on the right) in a large Facebook study. In 2015, the journal Science published a research paper by Facebook scientists (Bakshy, Eytan; Messing, Solomon; Adamic, Lada, 2015, “Replication Data for: Exposure to Ideologically Diverse News and Opinion on Facebook”,http://dx.doi.org/10.7910/DVN/LDJ7MS, Harvard Dataverse, V2) which looked at how a subset of the social network’s users reacted to the news appearing in their feeds. Read more at the Wall Street Journal Blog.