Use of NON-PARAMETRIC Item Response Theory to develop a shortened version of the Positive and Negative Syndrome Scale (PANSS)

Table 9 Slopes and Item Biserial Correlation for General Psychopathology Subscale

Items	Slopes	Rank of Slopes	Item biserial correlation
G2.Anxiety	0.481	1	0.565
G14.Poor Impulse control	0.442	2	0.604
G4.Tension	0.437	3	0.630
G6.Depression	0.437	4	0.600
G9.Unusual Thought Content	0.437	5	0.605
G8.Uncooperative	0.431	6	0.617
G13.Disturbance of Volition	0.426	7	0.601
G1.Somatic Concern	0.395	8	0.541
G7.Motor Retardation	0.382	9	0.606
G10.Disorientation	0.382	10	0.441
G3.Guilt Feelings	0.377	11	0.431
G11.Poor Attention	0.377	12	0.567
G15.Preoccupation	0.377	13	0.438
G16.Active Social Avoidance	0.377	14	0.366
G5. Mannerisms and Posturing	0.373	15	0.463
G12.Lack of Judgment/Insight	0.350	16	0.381

Note. Slopes were extracted from TestGraf output and were rounded to three decimal
places. Similarities in the values of slopes are due to rounding (e.g. slope of G4 is
0.436681, slope of G6 is 0.436586, slope of G9 is 0.436546; slope of G7 is 0.381679, and slope for G10 is 0.381534; slopes for G3, G11, G15 and G16 are 0.377358, 0.377287, 0.377145, and 0.377003, respectively).

ISSN: 1471-244X