Number of studies identified in all survey as motivated by pattern, theory or application. Three studies were purely descriptive, lacking a hypothesis and were not included in the figure. The black bars indicate the number of studies within each category that tested more than one hypothesis. Bootstrapped 95% CI are provided in table 1.
Number of studies and bootstrapped 95% CI calculated for theory-motivated studies (theory), pattern-motivated studies (pattern) and application-motivated studies (application). Bootstrapped 95% CIs were also provided for studies that tested more than one hypothesis (there were no papers that tested more than one hypothesis classified as application-motivated study). Code for bootstrapping is provided in the electronic supplementary material.