Table 1.

An example of the application of the RAND/UCLA appropriateness method to one criterion (criterion one) from round one

Nine-point scale where 1–3=inappropriate, 4–6=neither appropriate nor inappropriate, 7–9=appropriate	Number of panellists rating this criterion (n=15)	Calculations, interpercentile range method41	Interpretation
1 2 3 4 5 6 7 8 9	1 1 1 5 5 2 Median=7.0	30th percentile=7.0 70th percentile=8.0, interpercentile range (IPR)=70th−30th percentile)=1.0, IPR central point (IPRCP)=30th+70th percentile divided by 2=7.5 Asymmetry index (AI)=(5−IPRCP) (as an absolute value)=2.5 IPRAS=(2.5+(AI×1.5))=6.1, where 2.5 is the IPR required for disagreement when perfect symmetry exists, and 1.5 is the correction factor for asymmetry	This criterion was accepted according to the median method because four or less panellists voted outside the three-point region containing the median The IPRAS (6.1) was greater than the IPR (1.0) indicating no disagreement. The larger the IPRAS, the less asymmetric the ratings