Table 1 Summarising Mann–Whitney U -test... | Emerald Publishing

Table 1

Summarising Mann–Whitney U-test results for linguistic features with Cliff’s delta values

Feature	U-statistic	p	Cliff’s delta	AI mean	Non-AI mean
Punctuation count	4948693.0	5.85 × 10^−56***	0.242	45.570	37.199
Sentence count	4714464.0	7.19 × 10^−33***	0.183	18.987	16.356
Uppercase character ratio	3373993.5	2.41 × 10^−23***	−0.153	0.033	0.043
Type-token ratio	3382952.0	1.04 × 10^−22***	−0.151	0.624	0.640
Average sentence length	3402999.5	2.53 × 10^−21***	−0.146	22.400	25.704
Character count	4529449.5	4.98 × 10^−19***	0.137	2592.177	2379.091
Word count	4434613.5	1.78 × 10^−13***	0.113	400.749	374.637
Flesch Reading Ease	3576121.5	2.86 × 10^−11***	−0.102	40.674	41.357
Flesch-Kincaid grade	3888791.5	0.122	−0.024	13.151	13.876
AI detection score (DeskLib)	2549323.0	0.539	−0.011	0.523	0.533
Exclamation count	3964664.5	0.734	−0.005	0.812	0.935

Feature	U-statistic	p	Cliff’s delta	AI mean	Non-AI mean
Punctuation count	4948693.0	5.85 × 10^−56***	0.242	45.570	37.199
Sentence count	4714464.0	7.19 × 10^−33***	0.183	18.987	16.356
Uppercase character ratio	3373993.5	2.41 × 10^−23***	−0.153	0.033	0.043
Type-token ratio	3382952.0	1.04 × 10^−22***	−0.151	0.624	0.640
Average sentence length	3402999.5	2.53 × 10^−21***	−0.146	22.400	25.704
Character count	4529449.5	4.98 × 10^−19***	0.137	2592.177	2379.091
Word count	4434613.5	1.78 × 10^−13***	0.113	400.749	374.637
Flesch Reading Ease	3576121.5	2.86 × 10^−11***	−0.102	40.674	41.357
Flesch-Kincaid grade	3888791.5	0.122	−0.024	13.151	13.876
AI detection score (DeskLib)	2549323.0	0.539	−0.011	0.523	0.533
Exclamation count	3964664.5	0.734	−0.005	0.812	0.935

Note(s): Asterisks denote statistical significance: *p < 0.05, **p < 0.01, ***p < 0.001. No symbol indicates p ≥ 0.05