Table 3.

On the logit scale of Rasch model, the conversion from the correct items answered to the estimated ASD knowledge level (θ)

Correct quantities of 30	Accuracy of 30 items (%)	Estimated ASD knowledge score(θ)
4	13.33	-2.660
5	16.67	-2.385
6	20.00	-2.144
7	23.33	-1.926
8	26.67	-1.725
9	30.00	-1.535
10	33.33	-1.355
11	36.67	-1.181
12	40.00	-1.012
13	43.33	-0.846
14	46.67	-0.682
15	50.00	-0.517
16	53.33	-0.352
17	56.67	-0.185
18	60.00	-0.014
19	63.33	0.161
20	66.67	0.342
21	70.00	0.533
22	73.33	0.735
23	76.67	0.951
24	80.00	1.186
25	83.33	1.446
26	86.67	1.742
27	90.00	2.090
28	93.33	2.526

θ value is based on logit's estimation of accurate scale rather than strict ordinal value.