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Table 1 A summary of items with Differential Item Functioning

From: Using differential item functioning to evaluate potential bias in a high stakes postgraduate knowledge based assessment

Diet Total Ethnicity Sex Both
   Negligible Medium Large Negligible Medium Large Negligible Medium Large
2011 (1) 10 6    4      
2011 (2) 5 5         
2011 (3) 33 20    10    3   
2012 (1) 16 9 1   5    1   
2012 (2) 8 3    5      
2012 (3) 26 3    22 1     
2013 (1) 8 3    4 1     
2013 (2) 10 5    5      
2013 (3) 15 5 1   8    1   
2014 (1) 22 7    12    3   
2014 (2) 6 4    2      
2014 (3) 42 10    29 2 1    
2015 (1) 6 5    1      
2015 (2) 10 2    7 1     
Combined 217 87 2 0 114 5 1 8 0 0
  1. Note: Following the convention on effect sizes for DIF described by Magis et al., effect sizes below the medium threshold are classed as negligible rather than small. Blanks indicate no items of that magnitude. “Total” refers to total number of significant DIF tests. As some items exhibited DIF for both ethnicity and sex, the total number of items identified as problematic is slightly lower