EQR (presence/absence) versus EQR (abundance classes). Comparison of macroinvertebrate EQR scores in standard assessment using abundance classes and EQR scores in simulated scenarios with presence/absence data for (A) natural lentic waters (lakes, n=354), (B) natural lotic waters (streams and rivers, n=507) and (C) artificial waters (ditches and canals, n=919). Coloured boxes indicate EQR quality classes: “bad” (red), “poor” (orange), “moderate” (yellow), “good” (green) and “high” (blue). For artificial water bodies, there are only four quality classes, with “good” representing scores between 0.6 and 1.0. For all comparisons, the EQR scores of abundance class data and presence/absence data was significantly correlated (Pearson correlation, p <0.001). Pearson correlation values are provided in the panels.