measure of dispersion inter quartile range Alejandra Gonzalez-Beltran IQR(x, na.rm = FALSE, type = 7) http://stat.ethz.ch/R-manual/R-patched/library/stats/html/IQR.html Orlaith Burke Philippe Rocca-Serra STATO. adapted from wikipedia, wolfram alpha and oxford dictionary of statistics The interquartile range is a data item which corresponds to the difference between the upper quartile (3rd quartile) and lower quartile (1st quartile). The interquartile range contains the second quartile or median. The interquartile range is a data item providing a measure of data dispersion. ready for release