tended toward significanceP = 0.106
A significant positive linear correlation of the learning index values was observed for observers 1 and 3 ( r o1 = 0.729, P = 0.017; r o3 = 0.711, P = 0.021), whereas the experienced observer merely tended toward significance ( r o2 = 0.541, P = 0.106; Fig. 4 ).