X-Git-Url: https://pintos-os.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=doc%2Fstatistics.texi;h=93adb65aa158a358ba85e19cb0cde6e2a0c02575;hb=b5d60d6aabbec19bafeba0df8db98a9ac804dcf6;hp=c475f306b3644431b9e248e629b6e04b8b550b3b;hpb=38b40b6e700680ede4e2f6203e1200ad4197b4b4;p=pspp-builds.git diff --git a/doc/statistics.texi b/doc/statistics.texi index c475f306..93adb65a 100644 --- a/doc/statistics.texi +++ b/doc/statistics.texi @@ -681,8 +681,11 @@ is used. @menu * BINOMIAL:: Binomial Test * CHISQUARE:: Chisquare Test -* WILCOXON:: Wilcoxon Signed Ranks Test +* FRIEDMAN:: Friedman Test +* KRUSKAL-WALLIS:: Kruskal-Wallis Test +* RUNS:: Runs Test * SIGN:: The Sign Test +* WILCOXON:: Wilcoxon Signed Ranks Test @end menu @@ -762,20 +765,77 @@ sum of the frequencies need not be 1. If no /EXPECTED subcommand is given, then then equal frequencies are expected. -@node WILCOXON -@subsection Wilcoxon Matched Pairs Signed Ranks Test -@comment node-name, next, previous, up -@vindex WILCOXON -@cindex wilcoxon matched pairs signed ranks test + +@node FRIEDMAN +@subsection Friedman Test +@vindex FRIEDMAN +@cindex Friedman test @display - [ /WILCOXON varlist [ WITH varlist [ (PAIRED) ]]] + [ /FRIEDMAN = varlist ] @end display -The /WILCOXON subcommand tests for differences between medians of the +The Friedman test is used to test for differences between repeated measures when there is no indication that the distributions are normally distributed. + +A list of variables which contain the measured data must be given. The procedure prints the sum of ranks for each variable, the test statistic and its significance. + +@node KRUSKAL-WALLIS +@subsection Kruskal-Wallis Test +@vindex KRUSKAL-WALLIS +@vindex K-W +@cindex Kruskal-Wallis test + +@display + [ /KRUSKAL-WALLIS = varlist BY var (lower, upper) ] +@end display + +The Kruskal-Wallis test is used to compare data from an +arbitrary number of populations. It does not assume normality. +The data to be compared are specified by @var{varlist}. +The categorical variable determining the groups to which the +data belongs is given by @var{var}. The limits @var{lower} and +@var{upper} specify the valid range of @var{var}. Any cases for +which @var{var} falls outside [@var{lower}, @var{upper}] will be +ignored. + +The mean rank of each group as well as the chi-squared value and significance +of the test will be printed. +The abbreviated subcommand K-W may be used in place of KRUSKAL-WALLIS. + + +@node RUNS +@subsection Runs Test +@vindex RUNS +@cindex runs test + +@display + [ /RUNS (@{MEAN, MEDIAN, MODE, value@}) varlist ] +@end display + +The /RUNS subcommand tests whether a data sequence is randomly ordered. + +It works by examining the number of times a variable's value crosses a given threshold. +The desired threshold must be specified within parentheses. +It may either be specified as a number or as one of MEAN, MEDIAN or MODE. +Following the threshold specification comes the list of variables whose values are to be +tested. + +The subcommand shows the number of runs, the asymptotic significance based on the +length of the data. + +@node SIGN +@subsection Sign Test +@vindex SIGN +@cindex sign test + +@display + [ /SIGN varlist [ WITH varlist [ (PAIRED) ]]] +@end display + +The /SIGN subcommand tests for differences between medians of the variables listed. -The test does not make any assumptions about the variances of the samples. -It does however assume that the distribution is symetrical. +The test does not make any assumptions about the +distribution of the data. If the @code{WITH} keyword is omitted, then tests for all combinations of the listed variables are performed. @@ -789,20 +849,20 @@ If the @code{WITH} keyword is given, but the of variable preceding @code{WITH} against variable following @code{WITH} are performed. - -@node SIGN -@subsection Sign Test -@vindex SIGN -@cindex sign test +@node WILCOXON +@subsection Wilcoxon Matched Pairs Signed Ranks Test +@comment node-name, next, previous, up +@vindex WILCOXON +@cindex wilcoxon matched pairs signed ranks test @display - [ /SIGN varlist [ WITH varlist [ (PAIRED) ]]] + [ /WILCOXON varlist [ WITH varlist [ (PAIRED) ]]] @end display -The /SIGN subcommand tests for differences between medians of the +The /WILCOXON subcommand tests for differences between medians of the variables listed. -The test does not make any assumptions about the -distribution of the data. +The test does not make any assumptions about the variances of the samples. +It does however assume that the distribution is symetrical. If the @code{WITH} keyword is omitted, then tests for all combinations of the listed variables are performed.