POS Entropy ( PosH ) 0.55 0.02 0.21 -0.20 0.18 -0.11 0.22 1.00 0.16 -0.11 Derivation steps ( Step ) -0.05 0.11 0.38 -0.35 0.31 -0.16 0.32 0.16 1.00 -0.24 Word Length ( WLen ) 0.18 -0.29 -0.03 0.64 -0.72 0.56 0.02 -0.11 -0.24 1.00 Table 1 : Correlations between ( mean-centered ) predictors .