highly significantp < 10 –9
These effects are further amplified when adding another variable modification (search strategy D; Figure 2 ; mean 1.95). Because of the bimodal distribution of the target populations even after log(2) transformations, the Kruskal–Wallis test was employed for statistical testing and showed highly significant changes ( p < 10 –9 ) in both score distributions for search strategies C and D.