Table 2.

Shapley Additive Explanations (SHAP) for all tweets.

Token features			SHAP value, mean (95% CI)
Positive features for positive sentiment
	excited	0.480 (0.467 to 0.493)
	exciting	0.432 (0.418 to 0.446)
	enjoyed	0.367 (0.339 to 0.394)
	appreciate	0.314 (0.306 to 0.323)
	congratulations	0.297 (0.279 to 0.314)
	appreciated	0.286 (0.275 to 0.297)
	delighted	0.272 (0.253 to 0.291)
	enjoying	0.268 (0.244 to 0.291)
	lovely	0.251 (0.242 to 0.26)
	excellent	0.231 (0.225 to 0.237)
	liked	0.226 (0.221 to 0.232)
	blessed	0.226 (0.205 to 0.247)
	proud	0.218 (0.208 to 0.227)
	beautiful	0.216 (0.205 to 0.227)
	thankful	0.212 (0.197 to 0.227)
Negative features for positive sentiment
	bye	–0.082 (–0.094 to –0.069)
	deprived	–0.072 (–0.075 to –0.07)
	sucks	–0.056 (–0.058 to –0.053)
	disgusting	–0.048 (–0.053 to –0.043)
	scandals	–0.047 (–0.051 to –0.043)
	horrible	–0.043 (–0.045 to –0.041)
	iful	–0.042 (–0.054 to –0.031)
	frustrating	–0.040 (–0.042 to –0.038)
	suck	–0.040 (–0.044 to –0.036)
	unacceptable	–0.040 (–0.043 to –0.036)
	terrible	–0.039 (–0.041 to –0.038)
	suicide	–0.039 (–0.04 to –0.038)
	clar	–0.038 (–0.041 to –0.036)
	disappointed	–0.038 (–0.041 to –0.035)
	sco	–0.038 (–0.043 to –0.033)
Positive features for neutral sentiment
	smithsonian	0.100 (0.095 to 0.105)
	ashton	0.094 (0.089 to 0.099)
	spotify	0.085 (0.084 to 0.086)
	venture	0.080 (0.073 to 0.087)
	insp	0.077 (0.074 to 0.079)
	antioxidants	0.075 (0.067 to 0.083)
	beetles	0.071 (0.07 to 0.071)
	safely	0.070 (0.07 to 0.071)
	praise	0.066 (0.061 to 0.07)
	announces	0.064 (0.061 to 0.067)
	embracing	0.063 (0.062 to 0.064)
	playlist	0.063 (0.06 to 0.066)
	winston	0.062 (0.061 to 0.062)
	listener	0.061 (0.061 to 0.062)
	churchill	0.060 (0.059 to 0.06)
Negative features for neutral sentiment
	disgusting	–0.378 (–0.395 to –0.361)
	excited	–0.344 (–0.357 to –0.33)
	sucks	–0.334 (–0.341 to –0.327)
	shameful	–0.322 (–0.329 to –0.314)
	unacceptable	–0.313 (–0.331 to –0.294)
	horrible	–0.311 (–0.317 to –0.304)
	embarrassing	–0.307 (–0.328 to –0.287)
	disgrace	–0.305 (–0.323 to –0.288)
	exciting	–0.301 (–0.314 to –0.287)
	bullshit	–0.286 (–0.296 to –0.277)
	terrible	–0.286 (–0.291 to –0.28)
	unbelievable	–0.280 (–0.297 to –0.264)
	ridiculous	–0.275 (–0.282 to –0.269)
	disappointed	–0.271 (–0.284 to –0.258)
	unbearable	–0.268 (–0.286 to –0.25)
Positive features for negative sentiment
	disgusting	0.426 (0.407 to 0.445)
	sucks	0.389 (0.381 to 0.397)
	horrible	0.354 (0.347 to 0.361)
	shameful	0.354 (0.346 to 0.362)
	unacceptable	0.352 (0.333 to 0.371)
	disgrace	0.343 (0.324 to 0.361)
	embarrassing	0.342 (0.32 to 0.364)
	terrible	0.325 (0.319 to 0.331)
	bullshit	0.320 (0.31 to 0.331)
	unbelievable	0.314 (0.296 to 0.331)
	disappointed	0.309 (0.295 to 0.323)
	ridiculous	0.306 (0.299 to 0.314)
	unbearable	0.301 (0.281 to 0.321)
	suck	0.292 (0.274 to 0.31)
	stupid	0.291 (0.283 to 0.299)
Negative features for negative sentiment
	liked	–0.184 (–0.189 to –0.179)
	blessed	–0.146 (–0.161 to –0.13)
	enjoyed	–0.142 (–0.155 to –0.13)
	excited	–0.136 (–0.141 to –0.132)
	appreciate	–0.136 (–0.14 to –0.133)
	exciting	–0.131 (–0.136 to –0.126)
	bless	–0.121 (–0.126 to –0.115)
	enjoying	–0.117 (–0.129 to –0.105)
	appreciated	–0.115 (–0.12 to –0.111)
	insp	–0.112 (–0.116 to –0.108)
	thankful	–0.109 (–0.115 to –0.102)
	delighted	–0.107 (–0.114 to –0.101)
	proud	–0.106 (–0.11 to –0.102)
	lovely	–0.106 (–0.11 to –0.102)
	excellent	–0.104 (–0.106 to –0.101)