Table 3.
Kernel | Weight | Feature Space | 2008 | 2014 | Combined 2008/2014 | % Change 2008, 2014 | % Change 2008, Comb. | % Change 2014, Comb. |
---|---|---|---|---|---|---|---|---|
RBF | tf-idf | Min, Lex & CUI | 0.930 | 0.945 | 0.945 | 1.65 | 1.65 | 0.00 |
RBF | tf-idf | Min | 0.935 | 0.939 | 0.945 | 0.48 | 1.10 | 0.62 |
RBF | tf-idf | Lex | 0.935 | 0.933 | 0.945 | −0.16 | 1.10 | 1.26 |
RBF | Count | Lex | 0.940 | 0.945 | 0.945 | 0.55 | 0.55 | 0.00 |
RBF | tf-idf | Min & Lex | 0.940 | 0.945 | 0.940 | 0.55 | 0.00 | −0.55 |
RBF | Count | Min, Lex & CUI | 0.915†† | 0.945 | 0.940 | 3.30** | 2.73* | −0.55 |
RBF | Count | Min & Lex | 0.891†† | 0.945 | 0.940 | 6.04** | 5.46** | −0.55 |
RBF | Count | Min & CUI | 0.925 | 0.945 | 0.940 | 2.20 | 1.64 | −0.55 |
RBF | Count | Min | 0.940 | 0.921 | 0.940 | −1.97 | 0.00 | 2.01 |
RBF | Count | Lex & CUI | 0.935 | 0.940 | 0.940 | 0.55 | 0.55 | 0.00 |
Linear | tf-idf | Min & CUI | 0.934 | 0.871†† | 0.940 | −6.73** | 0.62 | 7.89** |
RBF | tf-idf | Lex & CUI | 0.940 | 0.945 | 0.939 | 0.55 | −0.07 | −0.62 |
RBF | tf-idf | Min & CUI | 0.915†† | 0.907†† | 0.939 | −0.87 | 2.66 | 3.56* |
Linear | Count | Min & CUI | 0.923 | 0.892†† | 0.933 | −3.41 | 1.11 | 4.68 |
Linear | Count | Min | 0.923 | 0.840†† | 0.933 | −9.05** | 1.11 | 11.18** |
Linear | Count | Lex | 0.928 | 0.912† | 0.933 | −1.71 | 0.56 | 2.31 |
Linear | Count | Min, Lex & CUI | 0.923 | 0.898† | 0.928 | −2.69 | 0.55 | 3.34 |
RBF | tf-idf | CUI | 0.928 | 0.886†† | 0.928 | −4.49** | 0.00 | 4.70** |
Linear | tf-idf | Lex | 0.929 | 0.913†† | 0.926 | −1.69 | −0.35 | 1.36 |
Linear | Count | Min & Lex | 0.909†† | 0.940 | 0.922 | 3.39** | 1.44 | −1.88 |
Linear | tf-idf | Min | 0.940 | 0.906†† | 0.921 | −3.62* | −1.97 | 1.71 |
Linear | tf-idf | Min, Lex & CUI | 0.899†† | 0.906†† | 0.920† | 0.78 | 2.40 | 1.61 |
Linear | tf-idf | Min & Lex | 0.940 | 0.913†† | 0.905†† | −2.83 | −3.71** | −0.91 |
Linear | Count | Lex & CUI | 0.945 | 0.892†† | 0.903†† | −5.66** | −4.47** | 1.27 |
Linear | tf-idf | Lex & CUI | 0.939 | 0.878†† | 0.894†† | −6.51** | −4.80** | 1.83 |
Linear | tf-idf | CUI | 0.867†† | 0.846†† | 0.821†† | −2.42 | −5.26* | ††2.92 |
RBF | Count | CUI | 0.820†† | 0.385†† | 0.755†† | −53.11** | −7.96 | 96.29** |
Linear | Count | CUI | 0.693†† | 0.316†† | 0.370†† | −54.44** | −46.57** | 17.28 |
percent change significant at alpha = 0.05
percent change significant at alpha = 0.1
statistically significantly different from highest performing model (emphasized above) at alpha = 0.05
statistically significantly different from highest performing model (emphasized above) at alpha =0.1
Note: For visual reference, models which are not statistically significantly different from the emphasized model at alpha = 0.1 are shaded in dark grey. Models which are not statistically significantly different from the emphasized model at alpha = 0.05 are shaded in light grey.