From: To test or not to test: Preliminary assessment of normality when comparing two independent samples
Strategy I | Strategy II | ||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|
α pre | n = 10 | n = 20 | n = 30 | n = 40 | n = 50 | n = 10 | n = 20 | n = 30 | n = 40 | n = 50 | |
Exponential distribution | |||||||||||
.100 | .050 | .050 | .048 | .049 | .048 | .053 | .050 | .048 | .049 | .048 | |
.050 | .053 | .050 | .048 | .049 | .050 | .055 | .052 | .048 | .049 | .050 | |
.010 | .054 | .054 | .048 | .049 | .050 | .054 | .054 | .048 | .049 | .050 | |
.005 | .050 | .056 | .050 | .048 | .049 | .050 | .055 | .049 | .048 | .049 | |
Uniform distribution | |||||||||||
.100 | .049 | .050 | .047 | .049 | .049 | .052 | .051 | .048 | .049 | .049 | |
.050 | .051 | .050 | .050 | .049 | .048 | .053 | .051 | .051 | .050 | .048 | |
.010 | .051 | .050 | .051 | .050 | .051 | .051 | .051 | .052 | .051 | .051 | |
.005 | .052 | .049 | .049 | .051 | .050 | .052 | .050 | .050 | .052 | .050 | |
Normal distribution | |||||||||||
.100 | .050 | .052 | .052 | .051 | .052 | .051 | .052 | .053 | .051 | .051 | |
.050 | .051 | .051 | .051 | .051 | .051 | .051 | .051 | .051 | .051 | .050 | |
.010 | .049 | .051 | .051 | .051 | .051 | .050 | .051 | .051 | .051 | .051 | |
.005 | .051 | .050 | .049 | .050 | .050 | .051 | .050 | .049 | .050 | .050 |