Table 5 The descriptive statistics for EM-CBM and CBM-R probes

From: A comparison of two estimation algorithms for Samejima’s continuous IRT model

  N Mean SD Skew. Kurt. Min Max Correlation
NI QD QA P1 P2 P3
NI 2,808 27.51 14.75 0.57 0.07 0 90 1 .70 .56 .64 .64 .62
QD 2,810 20.61 9.17 0.13 −0.17 0 54   1 .57 .50 .49 .48
QA 2,808 11.60 4.30 0.77 2.94 0 38    1 .45 .45 .45
P1 2,808 20.18 26.31 2.34 5.87 0 180     1 .97 .96
P2 2,810 22.67 33.16 2.71 8.29 0 251      1 .98
P3 2,810 21.92 32.46 2.71 8.06 0 228       1
  1. Note. NI, number identification; QD, quantity discrimination; QA, quantity array; P1, reading passage 1; P2, reading passage 2; P3, reading passage 3