X-Git-Url: https://pintos-os.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=doc%2Fstatistics.texi;h=a67402c0e13bd178dc720078f5cf819ee829e160;hb=6fb519761f5f942e598cfd8570c52594c9456ba3;hp=28398fb75e4a5c8abf82085a557715b6049bd796;hpb=7751519f5ca0b6106fe3d611010a70804677ab86;p=pspp diff --git a/doc/statistics.texi b/doc/statistics.texi index 28398fb75e..a67402c0e1 100644 --- a/doc/statistics.texi +++ b/doc/statistics.texi @@ -14,6 +14,7 @@ far. * ONEWAY:: One way analysis of variance. * RANK:: Compute rank scores. * REGRESSION:: Linear regression. +* RELIABILITY:: Reliability analysis. @end menu @node DESCRIPTIVES @@ -232,7 +233,7 @@ EXAMINE /PLOT=@{BOXPLOT, NPPLOT, HISTOGRAM, ALL, NONE@} /CINTERVAL n /COMPARE=@{GROUPS,VARIABLES@} - /ID=@{case_number, var_name@} + /ID=var_name /@{TOTAL,NOTOTAL@} /PERCENTILE=[value_list]=@{HAVERAGE, WAVERAGE, ROUND, AEMPIRICAL, EMPIRICAL @} /MISSING=@{LISTWISE, PAIRWISE@} [@{EXCLUDE, INCLUDE@}] @@ -271,6 +272,12 @@ If /COMPARE=VARIABLES is specified, then one plot per factor is produced, each each containing one boxplot per dependent variable. If the /COMPARE subcommand is ommitted, then PSPP uses the default value of /COMPARE=GROUPS. + +The ID subcommand also pertains to boxplots. If given, it must +specify a variable name. Outliers and extreme cases plotted in +boxplots will be labelled with the case from that variable. Numeric or +string variables are permissible. If the ID subcommand is not given, +then the casenumber will be used for labelling. The CINTERVAL subcommand specifies the confidence interval to use in calculation of the descriptives command. The default it 95%. @@ -831,3 +838,50 @@ user-missing are to be excluded from the rank scores. A setting of INCLUDE means they are to be included. The default is EXCLUDE. @include regression.texi + + +@node RELIABILITY +@section RELIABILITY + +@vindex RELIABILITY +@display +RELIABILITY + /VARIABLES=var_list + /SCALE (@var{name}) = @{var_list, ALL@} + /MODEL=@{ALPHA, SPLIT[(N)]@} + /SUMMARY=@{TOTAL,ALL@} + /MISSING=@{EXCLUDE,INCLUDE@} +@end display + +@cindex Cronbach's Alpha +The @cmd{RELIABILTY} command performs reliablity analysis on the data. + +The VARIABLES subcommand is required. It determines the set of variables +upon which analysis is to be performed. + +The SCALE subcommand determines which variables reliability is to be +calculated for. If it is omitted, then analysis for all variables named +in the VARIABLES subcommand will be used. +Optionally, the @var{name} parameter may be specified to set a string name +for the scale. + +The MODEL subcommand determines the type of analysis. If ALPHA is specified, +then Cronbach's Alpha is calculated for the scale. If the model is SPLIT, +then the variables are divided into 2 subsets. An optional parameter +@var{N} may be given, to specify how many variables to be in the first subset. +If @var{N} is omitted, then it defaults to one half of the variables in the +scale, or one half minus one if there are an odd number of variables. +The default model is ALPHA. + +By default, any cases with user missing, or system missing values for +any variables given +in the VARIABLES subcommand will be omitted from analysis. +The MISSING subcommand determines whether user missing values are to +be included or excluded in the analysis. + +The SUMMARY subcommand determines the type of summary analysis to be performed. +Currently there is only one type: SUMMARY=TOTAL, which displays per-item +analysis tested against the totals. + + +