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1 vote

Adaptive sample size for determining the significance of difference between two non-parametric distributions

I recommend this chapter in Daniel Lakens online book Improving your statistical inferences. The problem you need to be aware of when looking at data multiple times is inflated type-1 error rates. Or ...
• 106

Required sample size for exact McNemar test and for phi coefficient (power analysis)

I Googled "Power analysis McNemar test" and found this web page from ScaleStatistics, describing, in detail, how to do it in GPower. It allows both directional and non-directional tests. I ...
• 110k

Sample size estimation, stumped

This is an age old dilemma. It's all up to the way you want to pose the problem. First, do you have a fixed maximal model in mind based upon good science or are you hypothesis generating? I'm guessing ...
• 71
1 vote

Answer to sample size calculation is n1 = 2 + n2 = 2, can that be correct?

Given this huge difference in means relative to the standard deviations, that does seem possible. I couldn't find an R power calculator for a t-test with unequal variances, but I ran a program with ...
• 110k

How to calculate sample size for measuring level of agreement between devices?

An alternative approach would be to power your study as an equivalence study or a non-inferiority study. In this situation you would see if you can establish that the level of disagreement between the ...

How to calculate sample size for measuring level of agreement between devices?

Correlation is not a very good measure for this sort of thing. Why not? Because you can have high correlation without much agreement. If the new device consistently scores 1 unit higher than the gold ...
• 110k

Is Bayesian structural equation modelling better than maximum likelihood with smaller sample sizes?

The short answer to your question is that yes, when sample sizes are small, Bayesian SEM (BSEM) is preferable to traditional SEM, though only when reasonable priors are used. Recently, it has been ...
• 1,292

Sample size for 2-arm 2-stage trial: R package Trialsize vs rpact vs gsDesign

Sample size calculations for clinical trials, particularly superiority trials, can be complicated and is dependent on a number of characteristics and assumptions. In your scenario, you calculated the ...
• 56.8k

Pooling samples ahead of analysis - valid?

A few points beyond what @PBulls addressed (+1) in another answer. All of the cells you are examining come from a single donor, and thus any inferences you make will be restricted to that donor. Some ...
• 86.7k

Pooling samples ahead of analysis - valid?

I'm going to sidestep the (very valid!) concerns raised over technical vs. biological replication - if you're working with a cell line or inbred animals one might argue that you can only ever do ...
• 1,966
I don't get the same output as you do from G*Power; the lowest critical value I can achieve for your case 1 is $F>3.0819664$ using the provided parameters. Still, I think a key point is that you ...