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Table 1 RUMM2030 and R Output

From: A comparison of the polytomous Rasch analysis output of RUMM2030 and R (ltm/eRm/TAM/lordif)

    Item Fit Residuala Person Fit Residuala Chi-Squareb PSIc UNID T-Testd
Mean SD Mean SD Value (DF) p With without
RUMM 2030 PAIN Initial −0.8398 1.7301 −0.4845 0.9770 24.391 (20) 0.4969 0.9218 0.9135 4.6800%
Final −0.5336 1.1746 −0.4492 0.9127 18.5992 (20) 0.5480 0.8781 0.8644 2.3500%
SPECIFIC Initial −0.6052 2.1366 −0.4538 1.0702 54.0898 (30) 0.0045 0.9220 0.9033 4.7800%
Final −0.6266 1.5595 −0.4497 0.9686 50.3341 (20) 0.0002 0.9016 0.8699 3.6800%
USUAL Initial −0.4119 1.7207 −0.4544 0.9432 23.1212 (20) 0.2829 0.9208 0.8304 6.1600%
Final −0.3182 1.8380 −0.4642 1.0076 32.1662 (20) 0.0416 0.9217 0.8888 5.0700%
    Item Fit Residuala Person Fit Residuala    Cronbach’s Alphac Martin-Loefd
Mean SD Mean SD Value (DF) p
R PAIN Initial 1.63322 1.6195 −0.0447 1.89779    0.922 370.171(599) 1.0000
Final 1.7807 1.6219 0.0067 1.7558    0.872 239.851(339) 1.0000
SPECIFIC Initial 1.6092 0.80491 0.12174 1.37694    0.92 392.039(899) 1.0000
Final 1.7810 1.0349 0.1273 1.3960    0.8980 246.659(399) 1.0000
USUAL Initial 2.73459 1.43031 0.27866 1.84451    0.921 216.992(399) 1.0000
Final 2.9494 1.9276 0.2744 2.0210    0.9200 ERROR n/a
  1. a The fit residuals should have mean of 0 ± 2.5 and a standard deviation of 1 ± 2.5
  2. b The Chi-Square statistic should be small and statistically non-significant
  3. c A Person Separation Index (PSI) or Cronbach’s Alpha should be > 0.70 to be statistically reliable
  4. d Unidimensionality is present if the percentage of statistically significant t-tests is < 5% or if the result of the Martin-Loef test is not significant