Table 4.

Indicators of dimensionality and reliability of the bifactor model of PIUQ-9.

	General factor	Specific factors
	General problem	Obsession	Neglect + control disorder
ITALIAN VERSION
ECV	0.677	0.131	0.191
Ω	0.884	0.797	0.827
Ωh	0.782	0.226	0.134
H	0.840	0.489	0.788
GERMAN VERSION
ECV	0.570	0.174	0.257
Ω	0.858	0.765	0.809
Ωh	0.665	0.345	0.251
H	0.781	0.535	0.736
FRENCH VERSION
ECV	0.600	0.186	0.214
Ω	0.862	0.805	0.797
Ωh	0.682	0.344	0.231
H	0.804	0.572	0.621
POLISH VERSION
ECV	0.649	0.136	0.215
Ω	0.893	0.837	0.838
Ωh	0.729	0.254	0.246
H	0.843	0.526	0.641
SPANISH VERSION
ECV	0.700	0.126	0.174
Ω	0.898	0.851	0.836
Ωh	0.773	0.200	0.193
H	0.863	0.535	0.556
TURKISH VERSION
ECV	0.765	0.068	0.167
Ω	0.927	0.869	0.882
Ωh	0.852	0.150	0.114
H	0.902	0.322	0.846
HUNGARIAN VERSION
ECV	0.601	0.156	0.244
Ω	0.897	0.820	0.858
Ωh	0.719	0.338	0.238
H	0.830	0.558	0.878
ENGLISH VERSION
ECV	0.620	0.077	0.303
Ω	0.873	0.781	0.818
Ωh	0.706	0.141	0.294
H	0.826	0.318	0.963
GREEK VERSION
ECV	0.658	0.168	0.174
Ω	0.955	0.954	0.920
Ωh	0.817	0.367	0.168
H	0.912	0.859	0.938

PIUQ-9, Problematic Internet Use Questionnaire 9-items version; ECV, explained common variance; Ω, omega; Ωh, omega hierarchical; H, H index.