X-Git-Url: https://pintos-os.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=doc%2Fstatistics.texi;h=69576e55cbbc025d23887d0435708c6e09ac266f;hb=3b76a8aa4e808b2e6bdb792c369fda72a61304de;hp=0774d526d70653fbac37c0dbf2c416c763d76972;hpb=f199cb060728723c8cda2978b46070f8ac323dc6;p=pspp-builds.git diff --git a/doc/statistics.texi b/doc/statistics.texi index 0774d526..69576e55 100644 --- a/doc/statistics.texi +++ b/doc/statistics.texi @@ -9,6 +9,7 @@ far. * FREQUENCIES:: Frequency tables. * EXAMINE:: Testing data for normality. * CROSSTABS:: Crosstabulation tables. +* NPAR TESTS:: Nonparametric tests. * T-TEST:: Test hypotheses about means. * ONEWAY:: One way analysis of variance. * RANK:: Compute rank scores. @@ -304,7 +305,7 @@ there are many distinct values, then @cmd{EXAMINE} will produce a very large quantity of output. -@node CROSSTABS, T-TEST, EXAMINE, Statistics +@node CROSSTABS, NPAR TESTS, EXAMINE, Statistics @section CROSSTABS @vindex CROSSTABS @@ -493,11 +494,122 @@ Approximate T of uncertainty coefficient is wrong. Fixes for any of these deficiencies would be welcomed. -@node T-TEST, ONEWAY, CROSSTABS, Statistics +@node NPAR TESTS, T-TEST, CROSSTABS, Statistics +@section NPAR TESTS + +@vindex NPAR TESTS +@cindex nonparametric tests + +@display +NPAR TESTS + + nonparametric test subcommands + . + . + . + + [ /STATISTICS=@{DESCRIPTIVES@} ] + + [ /MISSING=@{ANALYSIS, LISTWISE@} @{INCLUDE, EXCLUDE@} ] +@end display + +NPAR TESTS performs nonparametric tests. +Non parametric tests make very few assumptions about the distribution of the +data. +One or more tests may be specified by using the corresponding subcommand. +If the /STATISTICS subcommand is also specified, then summary statistics are +produces for each variable that is the subject of any test. + + +@menu +* BINOMIAL:: Binomial Test +* CHISQUARE:: Chisquare Test +@end menu + + +@node BINOMIAL, CHISQUARE, NPAR TESTS, NPAR TESTS +@subsection Binomial test +@vindex BINOMIAL +@cindex binomial test + +@display + [ /BINOMIAL[(p)]=var_list[(value1[, value2)] ] ] +@end display + +The binomial test compares the observed distribution of a dichotomous +variable with that of a binomial distribution. +The variable @var{p} specifies the test proportion of the binomial +distribution. +The default value of 0.5 is assumed if @var{p} is omitted. + +If a single value appears after the variable list, then that value is +used as the threshold to partition the observed values. Values less +than or equal to the threshold value form the first category. Values +greater than the threshold form the second category. + +If two values appear after the variable list, then they will be used +as the values which a variable must take to be in the respective +category. +Cases for which a variable takes a value equal to neither of the specified +values, take no part in the test for that variable. + +If no values appear, then the the variable must assume dichotomous +values. +If more than two distinct, non-missing values for a variable +under test are encountered then an error occurs. + +If the test proportion is equal to 0.5, then a one tailed test is +reported. For any other test proportion, a one tailed test is +reported. +For one tailed tests, if the test proportion is less than +or equal to the observed proportion, then the significance of +observing the observed proportion or more is reported. +If the test proportion is more than the observed proportion, then the +significance of observing the observed proportion or less is reported. +That is to say, the test is always performed in the observed +direction. + +PSPP uses a very precise approximation to the gamma function to +compute the binomial significance. Thus, exact results are reported +even for very large sample sizes. + + + +@node CHISQUARE, , BINOMIAL, NPAR TESTS +@subsection Chisquare test +@vindex CHISQUARE +@cindex chisquare test + + +@display + [ /CHISQUARE=var_list[(lo,hi)] [/EXPECTED=@{EQUAL|f1, f2 @dots{} fn@}] ] +@end display + + +The chisquare test produces a chi-square statistic for the differences +between the expected and observed frequencies of the categories of a variable. +Optionally, a range of values may appear after the variable list. +If a range is given, then non integer values are truncated, and values +outside the specified range are excluded from the analysis. + +The /EXPECTED subcommand specifies the expected values of each +category. +There must be exactly one non-zero expected value, for each observed +category, or the EQUAL keywork must be specified. +You may use the notation @var{n}*@var{f} to specify @var{n} +consecutive expected categories all taking a frequency of @var{f}. +The frequencies given are proportions, not absolute frequencies. The +sum of the frequencies need not be 1. +If no /EXPECTED subcommand is given, then then equal frequencies +are expected. + + +@node T-TEST, ONEWAY, NPAR TESTS, Statistics @comment node-name, next, previous, up @section T-TEST @vindex T-TEST + @display T-TEST /MISSING=@{ANALYSIS,LISTWISE@} @{EXCLUDE,INCLUDE@}