Can a percentile score be estimated from a COMLEX-USA 3-digit score?
Once a full-year testing cycle is complete, a 3-digit score can be converted to percentile using the conversion tool on the home page of the NBOME web site (www.nbome.org). Prior to that, the formula and table below can be used to estimate a percentile score from a 3-digit COMLEX-USA score. In normal situations, a score’s distance from mean in terms of standard deviation implies a percentile rank. A COMLEX 3-digit score’s distance from the mean in terms of standard deviation can be computed in the following way: (3 digit score – Mean)/Standard Deviation = distance from mean For example, the mean for COMLEX Level 1 is 500 and the current standard deviation is 81. A score of 480 is -.247 deviations from the mean ((480-500)/81= -.247) or approximately .25 standard deviation below the mean. The table below converts a few 3-digit scores to percentiles. From this table, it can be seen that the percentile for a score of 480 for COMLEX Level 1 is between 30 and 50. It would be a reasonable est
