Table 4.

Results of hierarchical linear multiple regression models.

Dependent variable = swimming competence
Step	Independent variables	β	95% CI of B	F	ΔF	R 2	ΔR2	VIF
Demographic factors
1	Age	0.171**	20.690 to 32.551	25.378**	N/A	0.036	N/A	1.027
	Sex	−0.049**	−60.951 to −8.378		1.000
	Parents' highest education	0.059**	8.130 to 27.842		1.048
	Family Income	0.037	0.591 to 25.340		1.038
Swimming experience
2	Years of swimming	−0.054**	−11.433 to −4.441	66.038**	102.928**	0.162	0.126	1.028
	Frequency of swimming	0.304**	14.834 to 32.525					1.482
	Swimming duration	0.051*	−0.014 to 1.067					1.443
	Winter swimming	−0.044*	−60.303 to −4.562					1.294
Swimming location
2	Public swimming pool	−0.042*	−58.707 to −13.848	19.535**	14.478**	0.060	0.025	1.049
	School swimming pool	0.025	2.361 to 125.652					1.036
	Club swimming pool	−0.139**	−165.500 to −75.154					1.052
	Estate swimming pool	0.031	−1.160 to 47.519					1.039
	Beach	0.046*	1.239 to 97.989					1.053
Swimming accessibility
2	Public swimming pool	0.003	−29.380 to 44.213	16.989**	10.057**	0.053	0.017	1.056
	School swimming pool	−0.004	−106.842 to 68.074		1.023
	Club swimming pool	−0.117**	−128.647 to −60.982		1.036
	Estate swimming pool	0.044*	6.093 to 55.270		1.039
	Beach	0.047*	3.550 to 76.367		1.062
Learning experience
2	Learning experience	−0.004	−5.624 to 3.648	20.194**	0.048**	0.035	0.000	1.003

Step 1 was identical throughout the three models. CI of B, 95% bias-corrected and accelerated bootstrap confidence. VIF, variance inflation factor. Swimming duration, duration of each swimming session in minutes. Learning experience, “Learn swimming from whom?”. PE teacher, physical education teacher. *p <0.05; **p <0.01; N/A - not applicable.