Table 2. Result of sentiment analysis

Course	Doc	Doc length	Sentiment words							Senti score
			Pos(+2)	Pos(+1)	Neg(-1)	Neg(-2)	Pos count(%)	Neg count(%)	Senti total
8	257	214.29	698	673	261	167	1,371(76.21)	428(23.79)	1,799	1,474
21	183	212.82	533	435	158	114	968(78.06)	272(21.94)	1,240	985
1	234	114.95	333	325	101	65	658(79.85)	166(20.15)	824	760
9	140	160.84	325	249	136	72	574(73.40)	208(26.60)	782	619
7	163	169.05	273	290	115	101	563(72.27)	216(27.73)	779	519
10	123	170.22	236	221	80	78	457(74.31)	158(25.69)	615	457
18	136	227.68	290	287	137	138	577(67.72)	275(32.28)	852	454
3	172	104.13	207	199	81	67	406(73.29)	148(26.71)	554	398
2	215	107.78	199	178	88	80	377(69.17)	168(30.83)	545	328
15	86	212.12	169	192	84	41	361(74.28)	125(25.72)	486	364
19	127	110.60	186	135	66	54	321(72.79)	120(27.21)	441	333
5	137	122.14	183	133	79	57	316(69.91)	136(30.09)	452	306
4	133	70.89	131	92	42	23	223(77.43)	65(22.57)	288	266
6	94	122.17	137	135	51	54	272(72.15)	105(27.85)	377	250
11	80	181.46	143	141	70	59	284(68.77)	129(31.23)	413	239
14	80	164.18	157	124	54	73	281(68.87)	127(31.13)	408	238
20	118	130.80	136	128	67	48	264(69.66)	115(30.34)	379	237
12	94	134.82	101	158	34	49	259(75.73)	83(24.27)	342	228
16	63	157.65	99	82	28	40	181(72.69)	68(27.31)	249	172
13	79	79.03	80	65	23	16	145(78.80)	39(21.20)	184	170
17	61	136.61	77	54	52	38	131(59.28)	90(40.72)	221	80
Total_ave	132	147.82	223	205	86	68	428(72.6)	154(27.4)	582.4	422.7

'Doc Length' refers to the average number of words in documents by course.