Table 2.

Estimates of discrimination and severity parameters for the Game Addiction Scale under the graded-response model with the LTM package.

Item	Discrimination, αia	Severity
		βi1	βi2	βi3	βi4	Spread
Salience	1.92	−0.04	0.83	1.58	2.29	2.33
Tolerance	2.03	−0.47	0.24	1.18	2.17	2.64
Mood modification	2.13	0.35	1.06	1.83	2.56	2.21
Relapse	2.93	0.59	1.20	1.90	2.61	2.02
Withdrawal	2.56	0.92	1.64	2.42	3.15	2.23
Conflict	2.83	0.79	1.45	2.23	2.88	2.09
Problems	2.19	0.65	1.38	2.23	2.93	2.28

^aα_i reflects the ability of item i to discriminate between different levels of game addiction severity (θ).

^bβ_ik is the k th cutoff point for item i. It is interpreted as the standardized level of game addiction severity where subsequent response options become more probable than the previous option.