{smcl} {* 18mar2005}{...} {cmd:help fprank} {hline} {title:Title} {p2colset 5 15 17 2}{...} {p2col :{hi:fprank} {hline 2}}Two-Sample Fligner-Policello Robust Rank Order Test {p_end} {p2colreset}{...} {title:Syntax} {p 8 19 2} {cmd:fprank} {varname} {ifin}{cmd:,} {cmd:by(}{it:groupvar}{cmd:)} {synoptset 21 tabbed}{...} {synopthdr:options} {synoptline} {syntab:Main} {p2coldent:* {opt by(groupvar)}}grouping variable{p_end} {synoptline} {p2colreset}{...} {p 4 6 2}* {opt by(groupvar)} is required.{p_end} {p 4 6 2}{opt by} may be used with the above commands; see {helpb by}.{p_end} {title:Description} {pstd} {cmd:fprank} tests the hypothesis that two independent groups are sampled from the same population using the robust rank-order test which is a useful alternative of the Mann-Whitney-Wilcoxon test for non-normal populations with unequal variances. This test assumes neither normality, nor equal variances, nor equal shape. {pstd} {cmd:fprank} provides the asymptotic p-value which is based on the standard normal distribution. It should be noted, however, that the asymptotic p-value may not be adequate when both samples are <= 12. To obtain the significance of the statistic U when sample sizes are (<=12), refer to the table of critical Values of U for the robust rank order test found in the references below. {title:Examples} {psee}{cmd:. fprank scores, by(group)}{p_end} {title:References} {p 4 4 2}Siegel, S. & Castellan, N.J.Jr.(1988). {it}Nonparametric statistics for the behavioral sciences {sf} (2nd ed.). New York: McGraw-Hill. {p 4 4 2}Hollander, M & Wolfe, DA. (1999). {it}Nonparametric statistical methods {sf} (2nd ed.). New York: Wiley. {p 4 4 2}Fligner, MA & Policello, GE. (1981). Robust rank procedures for the Behrens-Fisher problem. {it}Journal of the American Statistical Association, {sf} 76(373), 162-168. {p 4 4 2}The two data files attached to this package are from Siegel & Castellan (1988, pp 138-143). {title:Author} {p 4 4 2}Benmamoun, Mamoun, Saint Louis University , Saint Louis, MO, U.S.A. Email {browse "mailto: vmamoun@yahoo.com": vmamoun@yahoo.com} if you observe any problem or if you have any comment or question. {title:Also See} {psee} Online: {helpb ranksum}, {helpb ttest} {p_end}