TABLE 2.

PYD qualities and Internet addiction test scores among Chinese children and adolescents at two waves.

Items	Wave 1		Wave 2		Test effect
	Mean 1	SD 1	Mean 2	SD 2	Mean 2–Mean 1	95% C.I.	t	P
PYD attributes
Cognitive-behavioral competence	5.02	0.75	5.00	0.81	−0.02	−0.04∼0.0009	−1.87	0.06
Prosocial attributes	5.05	0.82	5.04	0.86	−0.004	−0.025∼0.017	−0.39	0.699
Positive identity	4.80	0.93	4.76	0.97	−0.038	−0.06∼−0.016	−3.41	0.00065**
General PYD	5.01	0.71	4.97	0.77	−0.045	−0.06∼−0.028	−5.26	<0.01**
Total PYD	4.99	0.69	4.96	0.75	−0.033	−0.049∼−0.017	−4.01	<0.01**
Internet addiction
Young’s Internet addiction test	35.56	14.74	36.16	15.23	0.60	0.28∼0.93	3.68	0.0002**

PYD, Positive youth development; C.I., Confidence interval.

*p < 0.05; **p < 0.01.