Multiple Comparisons (Bonferroni & Tukey HSD) with Confidence Intervals
Zaiontz’s Method for Multiple Comparisons

Exercise:
Urine concentration of a certain substance (μg/day) in premature babies was measured to investigate the relation between urine substance concentration and gestational week.
The gestational weeks were divided into 3 week-ranges, which are ‘<28weeks, 29 – 32 weeks, and 33 – 36 weeks’. The urine concentrations of the substance were measured at ‘1 week (within 7 days after delivery), 2 weeks (7 – 13 days), and 3 weeks (14 – 27 days)’. Results are shown below.
Analyze whether there are statistically significant differences.

Comparative Verification Test

P-value (Factor A): StatFinale, 8.605E-09; SPSS, 0.000; EZR, 8.605E-09.
P-value (Factor B): StatFinale, 3.2406E-06; SPSS, 0.000; EZR, 3.2406E-06.
P-value (A * B): StatFinale, 0.4777; SPSS, 0.478; EZR, 0.4777.
Multiple comparisons and confidence intervals (CIs): Exact match
Multiple C & CIs (Bonferroni & Tukey HSD): StatFinale & SPSS
Multiple C & CIs (Zaiontz): StatFinale

Reports of SPSS & EZR