title: An empirical description of the dispersion of 5th and 95th percentiles in worldwide anthropometric data applied to estimating accommodation with unknown correlation values.
abstract: BACKGROUND
  Anthropometric data are assumed to have a Gaussian (Normal) distribution, but if non-Gaussian, accommodation estimates are affected. When data are limited, users may choose to combine anthropometric elements by Combining Percentiles (CP) (adding or subtracting), despite known adverse effects.
  
  
  OBJECTIVE
  This study examined whether global anthropometric data are Gaussian distributed. It compared the Median Correlation Method (MCM) of combining anthropometric elements with unknown correlations to CP to determine if MCM provides better estimates of percentile values and accommodation.
  
  
  METHODS
  Percentile values of 604 male and female anthropometric data drawn from seven countries worldwide were expressed as standard scores. The standard scores were tested to determine if they were consistent with a Gaussian distribution. Empirical multipliers for determining percentile values were developed.In a test case, five anthropometric elements descriptive of seating were combined in addition and subtraction models. Percentile values were estimated for each model by CP, MCM with Gaussian distributed data, or MCM with empirically distributed data.
  
  
  RESULTS
  The 5th and 95th percentile values of a dataset of global anthropometric data are shown to be asymmetrically distributed. MCM with empirical multipliers gave more accurate estimates of 5th and 95th percentiles values.
  
  
  CONCLUSIONS
  Anthropometric data are not Gaussian distributed. The MCM method is more accurate than adding or subtracting percentiles.
authors: Thomas J
authors: TJ
authors: Albin
authors: Peter
authors: P
authors: Vink
mesh_terms: D000704:Analysis of Variance; D000886:Anthropometry; D001837:Body Weights and Measures / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D007558:Italy; D007564:Japan; D007630:Kenya; D008297:Male; D009426:Netherlands; D016011:Normal Distribution; D056910:Republic of Korea; D013785:Thailand; D014481:United States
keywords: Summing percentiles; anthropometric models; combining anthropometric dimensions; subtracting percentiles