31.5 P-values: Comparing odds

The differences between the observated sample statistic (the sample OR) and the hypothesised population parameter (the population OR of one) is summarised by χ2=6.934 (approximately equivalent to z=2.63). Using the 68–95–99.7 rule, a small P-value is expected.

The corresponding two-tailed P-value reported by jamovi (Fig. 31.1, under the p column) and SPSS (Fig. 31.2, in the Asymptotic Significance (2-sided) column and Pearson Chi-Square row) is very small (0.008 to three decimals).

Recall that, for two-way tables of counts, the alternative hypotheses are always two-tailed, so a two-tailed P-value is always reported.

Click on the hotspots in the following image, to see what the SPSS output tells us.