Table 3. Proportion of document’s sentiment characteristic
| Course | Doc | Senti score | Positive | Negative | Neutral |
| Proportion(%) | Score_mean(SD) | Proportion(%) | Score_mean(SD) | Proportion(%) |
| 8 | 257 | 1,474 | 76.26 | 7.81(6.77) | 7.00 | -1.56(0.51) | 16.73 |
| 21 | 183 | 985 | 74.32 | 5.99(7.74) | 9.84 | -2.11(1.18) | 15.85 |
| 1 | 234 | 760 | 59.83 | 6.27(7.52) | 7.69 | -2.06(1.26) | 32.48 |
| 9 | 140 | 619 | 67.86 | 6.68(6.68) | 6.43 | -1.78(0.44) | 25.71 |
| 7 | 163 | 519 | 61.96 | 5.74(5.47) | 11.04 | -3.39(2.03) | 26.99 |
| 10 | 123 | 457 | 58.54 | 6.83(6.18) | 17.07 | -1.67(1.11) | 24.39 |
| 18 | 136 | 454 | 64.71 | 5.82(6.07) | 18.38 | -2.32(1.63) | 16.91 |
| 3 | 172 | 398 | 58.72 | 4.38(3.93) | 10.47 | -2.44(2.43) | 30.81 |
| 2 | 215 | 328 | 46.51 | 3.98(3.53) | 13.02 | -2.50(1.71) | 40.47 |
| 15 | 86 | 364 | 66.28 | 6.68(6.14) | 6.98 | -2.83(1.72) | 26.74 |
| 19 | 127 | 333 | 61.42 | 4.88(4.67) | 18.11 | -2.09(1.35) | 20.47 |
| 5 | 137 | 306 | 55.47 | 4.45(3.11) | 11.68 | -2.00(1.10) | 32.85 |
| 4 | 133 | 266 | 50.38 | 4.15(3.87) | 6.02 | -1.50(0.53) | 43.61 |
| 6 | 94 | 250 | 61.70 | 4.84(3.99) | 12.77 | -2.58(1.62) | 25.53 |
| 11 | 80 | 239 | 56.25 | 5.60(7.76) | 7.50 | -2.17(0.41) | 36.25 |
| 14 | 80 | 238 | 57.50 | 6.41(6.57) | 17.50 | -4.07(2.70) | 25.00 |
| 20 | 118 | 237 | 55.93 | 3.94(3.47) | 9.32 | -2.09(1.22) | 34.75 |
| 12 | 94 | 228 | 44.68 | 5.95(6.95) | 14.89 | -1.57(0.76) | 40.43 |
| 16 | 63 | 172 | 50.79 | 5.94(5.55) | 12.70 | -2.25(1.28) | 36.51 |
| 13 | 79 | 170 | 53.16 | 4.14(4.48) | 5.06 | -1.00(0) | 41.77 |
| 17 | 61 | 80 | 32.79 | 5.40(5.73) | 18.03 | -2.55(2.30) | 49.18 |
| Total_ave | 132 | 147.82 | 57.86 | - | 11.50 | - | 30.64 |