The CROSSTABS command can compute Goodman and Kruskal's lambda. It also calculates the standard error of lambda according to the formula for ASE0 given here: http://pic.dhe.ibm.com/infocenter/spssstat/v22r0m0/index.jsp?topic=%2Fcom.ibm.spss.statistics.algorithms%2Falg_crosstabs_measures.htm
This page gives an example of the SPSS calculation: http://www.csupomona.edu/~jlkorey/POWERMUTT/Topics/contingency_tables.html Here is PSPP syntax that should reproduce the given on that page: SET FORMAT F8.3. * From http://www.csupomona.edu/~jlkorey/POWERMUTT/Topics/contingency_tables.html. DATA LIST LIST NOTABLE/x y w. WEIGHT BY w. BEGIN DATA. 1 1 424 1 2 213 1 3 59 3 1 55 3 2 188 3 3 357 END DATA. Directional measures. #========================================#=====#===========#========#=========# #Category Statistic Type #Value|Asymp. Std.| Approx.| Approx.# # # | Error| T| Sig.# #----------------------------------------#-----+-----------+--------+---------# #Nominal by Lambda Symmetric # .423| .021| 15.281| # #Nominal # | | | # # x # .497| NaN| 15.986| # # Dependent # | | | # # y # .370| NaN| 16.339| # # Dependent # | | | # # ---------------------------#-----+-----------+--------+---------# # Goodman and x # .382| | | # # Kruskal tau Dependent # | | | # # y # .198| | | # # Dependent # | | | # #========================================#=====#===========#========#=========# However, the asymmetrics ASEs given above are wrong. The first NaN should be .024 and the second one should be .020 according to that example webpage. Worse, the ASEs given above don't match those calculated by other software. For example, if you enter the data above into http://vassarstats.net/newcs.html, you get the same lambda values .497 and .370 (well, to one extra digit), but ASEs .034 and .028, respectively. Can anyone explain how to calculate the asymptotic standard error of lambda in a way that matches the SPSS results? _______________________________________________ pspp-dev mailing list [email protected] https://lists.gnu.org/mailman/listinfo/pspp-dev
