Extended Data Fig. 2: Estimated total global numbers of all terrestrial protected area personnel, rangers and non-rangers according to two prediction methods.
From: Protected area personnel and ranger numbers are insufficient to deliver global expectations

Methods used are Linear Mixed Models (LMM) and Random Forests/Extremely Randomised Trees (RF/ETs). Five different values of coefficient are used for the imputation (see Methods). Error bars represent 95% prediction intervals.