## Power_80_20 [Power / Sample Size]

Hi,

» In the results it is also evident that the post-hoc statistical power (power_TOST) is less than 80%, this is because the estimated point is greater than 105%, considering that the sample size was estimated expecting a difference less than / equal to 5%.

There are 3 basic factors in power calc: sample size, CV and PE. In post-hoc analysis sample size is fixed, but do not forget about CV! So the conclusion is valid if CV is equal or less than expected

» However, the statistical power of the ANOVA (Power_80_20) supports that the sample size used in the study was adequate, since the values are greater than 90%.

I think it should go to the trash bin. That's a conclusion based on WNL output, right?

See this old thread

That 'magick power' is not a power of ANOVA (whenever it could be) but the result of equality test using delta = 20%. That test has much more power than PowerTOST, thus, the value is higher than the previous one.

You cannot assess the sample size using that test.

» In the results it is also evident that the post-hoc statistical power (power_TOST) is less than 80%, this is because the estimated point is greater than 105%, considering that the sample size was estimated expecting a difference less than / equal to 5%.

There are 3 basic factors in power calc: sample size, CV and PE. In post-hoc analysis sample size is fixed, but do not forget about CV! So the conclusion is valid if CV is equal or less than expected

» However, the statistical power of the ANOVA (Power_80_20) supports that the sample size used in the study was adequate, since the values are greater than 90%.

I think it should go to the trash bin. That's a conclusion based on WNL output, right?

See this old thread

That 'magick power' is not a power of ANOVA (whenever it could be) but the result of equality test using delta = 20%. That test has much more power than PowerTOST, thus, the value is higher than the previous one.

You cannot assess the sample size using that test.

—

Kind regards,

Mittyri

Kind regards,

Mittyri

### Complete thread:

- power_TOST vs. statistical power of the ANOVA MCelestino 2019-01-03 22:05
- Power_80_20mittyri 2019-01-04 00:24
- Power_80_20 MCelestino 2019-01-04 19:18
- Power_80_20 ElMaestro 2019-01-04 21:39

- Power_80_20 MCelestino 2019-01-04 19:18

- Power_80_20mittyri 2019-01-04 00:24