Table 4.
Kernel | Weight | Feature Space | 2008 | 2014 | Combined 2008/2014 | % Change 2008, 2014 | % Change 2008, Comb. | % Change 2014, Comb. |
---|---|---|---|---|---|---|---|---|
RBF | tf-idf | Min | 0.841†† | 0.896 | 0.878 | 6.54** | 4.37** | −2.03 |
RBF | tf-idf | Min, Lex & CUI | 0.827†† | 0.891 | 0.872 | 7.73** | 5.47** | −2.10 |
RBF | tf-idf | Min & Lex | 0.829†† | 0.883 | 0.871† | 6.62** | 5.12** | −1.41 |
Linear | tf-idf | Min & Lex | 0.805†† | 0.882 | 0.843†† | 9.62** | 4.77** | −4.42** |
Linear | tf-idf | Lex | 0.815†† | 0.881 | 0.844†† | 8.09** | 3.47** | −4.28** |
RBF | tf-idf | Lex | 0.748†† | 0.875† | 0.876 | 17.01** | 17.09** | 0.07 |
Linear | tf-idf | Min, Lex & CUI | 0.793†† | 0.875 | 0.846†† | 10.34** | 6.72** | −3.28* |
Linear | tf-idf | Min | 0.809†† | 0.872†† | 0.841†† | 7.87** | 3.96** | −3.63** |
Linear | tf-idf | Min & CUI | 0.788†† | 0.868†† | 0.861†† | 10.15** | 9.30** | −0.77 |
Linear | tf-idf | Lex & CUI | 0.780†† | 0.863†† | 0.851†† | 10.60** | 9.06** | −1.39 |
RBF | tf-idf | Min & CUI | 0.820†† | 0.863†† | 0.868† | 5.16** | 5.77** | 0.58 |
RBF | Count | Min | 0.727†† | 0.861†† | 0.830†† | 18.40** | 14.10** | −3.63 |
RBF | Count | Lex | 0.792†† | 0.858†† | 0.833†† | 8.37** | 5.14** | −2.97* |
RBF | Count | Lex & CUI | 0.765†† | 0.857†† | 0.837†† | 12.00** | 9.41** | −2.31 |
RBF | tf-idf | Lex & CUI | 0.782†† | 0.855†† | 0.881 | 9.29** | 12.68** | 3.10 |
Linear | Count | Lex & CUI | 0.737†† | 0.851†† | 0.791†† | 15.51** | 7.33** | −7.09** |
RBF | Count | Min & CUI | 0.696†† | 0.851†† | 0.830†† | 22.23** | 19.16** | −2.51 |
RBF | Count | Min & Lex | 0.670†† | 0.844†† | 0.843†† | 25.87** | 25.73** | −0.11 |
Linear | Count | Lex | 0.698†† | 0.841†† | 0.814†† | 20.47** | 16.66** | −3.16 |
Linear | Count | Min, Lex & CUI | 0.698†† | 0.840†† | 0.767†† | 20.32** | 9.86** | −8.69** |
Linear | Count | Min & Lex | 0.674†† | 0.835†† | 0.799†† | 23.89** | 18.51** | −4.34* |
RBF | Count | Min, Lex & CUI | 0.714†† | 0.832†† | 0.842†† | 16.57** | 17.89** | 1.13 |
Linear | Count | Min | 0.682†† | 0.825†† | 0.795†† | 21.05** | 16.62** | −3.66 |
Linear | Count | Min & CUI | 0.669†† | 0.824†† | 0.797†† | 23.30** | 19.20** | −3.32 |
RBF | tf-idf | CUI | 0.608†† | 0.689†† | 0.732†† | 13.29** | 20.43** | 6.30* |
Linear | tf-idf | CUI | 0.610†† | 0.674†† | 0.654†† | 10.65** | 7.31* | −3.01 |
RBF | Count | CUI | 0.631†† | 0.616†† | 0.616†† | −2.41 | −2.46 | −0.04 |
Linear | Count | CUI | 0.542†† | 0.538†† | 0.548†† | −0.65 | 1.23 | 1.89 |
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