- Effects of new Wikipedia articles are most evident in high similarity articles, suggesting that recent scientific literature were impacted by new scientific knowledge presented in Wikipedia 
- Wikipedia articles most frequently influence introduction and background of scientific articles published on new content 

University of Michigan - Ann Arbor

- Wrote new scientific Wikipedia articles for chemistry and econometrics
- Stratified the 43 chemistry articles into 3 blocks – article author, branch of knowledge, and types of topics. Within each block, half the articles were randomly assigned as treatment and the other half as control 
- Treatment articles uploaded to Wikipedia in January 2015
- Control articles were not uploaded onto Wikipedia 
- If there is causation, then new articles added to Wikipedia should have a greater impact on the scientific community compared to new articles in the control group 

Science is shaped by wikipedia experimental design

Thompson, N., & Hanley, D. (2018). Science is shaped by wikipedia: Evidence from a randomized control trial. https://papers.ssrn.com/sol3/papers.cfm?abstract_id=3039505. 

Science is shaped by wikipedia: Evidence from a randomized control trial

- After being uploaded, each chemistry article had an average of 4,400 views per month and in 2 years, treatment articles together had more than 2 million views 
- Control (green) shows rise in low similarity articles; fall in high similarity articles
- Treatment (blue) shows fall in low similarity articles; rise in high similarity articles 
- Significant coefficients indicate that one new Wikipedia article leads to a positive shift in scientific literature published 
- Concluded that introduction of new chemistry articles in Wikipedia caused an increase in scientific literature on those topics (scientists reading the new Wikipedia articles means impact of treatment articles on scientific literature is strong enough to imply causation)

Learn Before

Related