| Abstract: | Comparisons are made between the two values of the chisquare statistic in three dimensional contigency tables as defined respectively by the ‘multiplicative’ an ‘additive’ models of zero second order interaction. It is shown that in practice the two definitions frequently give comparable values for the statistics, and it is concluded that interaction measures, and paritioning of the overall association chisuare, are more useful than the considerable writing on the models' deficiencies would seem to indicate. There seems to be a slight bias in favour of the multiplicative model. |
