What is alpha error probability in G power?
The alpha level, or the Type I error rate, which is the probability of rejecting the null hypothesis when it is actually true. A common practice is to set it at the . 05 level. The pre-specified level of statistical power for calculating the sample size; this will be set to . 8.
What is the minimum sample size for statistical analysis?
100
The minimum sample size is 100 Most statisticians agree that the minimum sample size to get any kind of meaningful result is 100. If your population is less than 100 then you really need to survey all of them.
How to calculate the sample size for a power analysis?
The pre-specified level of statistical power for calculating the sample size; this will be set to .8. The pre-specified number of subjects for calculating the statistical power; this is the situation for Example 2.
When are unequal sample sizes are and are not a problem in ANOVA?
So if you have equal variances in your groups and unequal sample sizes, no problem. If you have unequal variances and equal sample sizes, no problem. The only problem is if you have unequal variances and unequal sample sizes.
Which is an example of a power analysis?
There are two different aspects of power analysis. One is to calculate the necessary sample size for a specified power as in Example 1. The other aspect is to calculate the power when given a specific sample size as in Example 2. Technically, power is the probability of rejecting the null hypothesis when the specific alternative hypothesis is true.
How are independent samples used in ANOVA?
Independent samples t-tests are essentially a simplificiation of a one-way ANOVA for only two groups. In fact, if you run your t-test as an ANOVA, you’ll get the same p-value. And the between-groups F statistic will be the square of the t statistic you got in your t-test.