Sam Wineburg asks this question during a talk in Sweden. (Actually, the crowd was there to hear a talk about Howard Zinn, but Wineburg called a last minute audible).
He begins by talking about his scholarly publications--articles that appeared in places like The Journal of American History and Cognitive Science (which rejects 99% of its submissions). But after receiving tenure, Wineburg wondered if he had really "changed the field" in the way that the administrators at his university had said he had done in their evaluation of his work. After publishing in these prestigious journals he wondered, as a professor of education, if his scholarship was really making an impact on ordinary teachers and school districts.
Then Wineburg met Roy Rosenzweig. The late scholar of digital history at George Mason University challenged him to speak to a broad reading public and to real teachers--men and women in the trenches who were actually teaching history to students and who were probably not reading his journal articles. Wineburg's discussions with Rosenzweig prompted him to create the website Historical Thinking Matters. Anyone who has used this resource knows its value in teaching students and history teachers how to think historically. I use it in a course I teach at Messiah College called "Teaching History."
The original goal of Historical Thinking Matters was to make the best kinds of historical thinking resources available to all students and teachers, especially those in underprivileged areas that lacked resources and funds. Unfortunately, Wineburg found that the material on the website was too complicated for students in less-quality schools. Instead of shrinking the gap between the best schools and the more "ordinary" schools, Wineburg worried that he may have actually widened the gap between these schools. It was a lesson learned.
Next Wineburg made an attempt to bring historical thinking and historical reading to the San Francisco Public Schools, a very diverse school district. He and his team performed an experiment that improved reading comprehension in the district by teaching students to interpret primary sources. He published his findings in The Journal of Curriculum Studies and Cognition & Instruction. Together these two publications reached about 30,000 people. But when he put the San Francisco curriculum, "Reading Like a Historian," on the web, it was downloaded 600,000 times in eighteen months.
Wineburg concludes that it is impossible to "change the field" unless scholars put their findings in an accessible form.
Watch the last five minutes of this video to learn about Wineburg's "Theory of Change." It has everything to do with the dissemination of knowledge through the Internet and social media. It also has something to do with lions and mosquitoes.