G*Power Sample Size Calculations: 5 Min Demo

How many participants do you need in your study? How can you design an efficient study? This video demonstrates an a priori power analysis / sample size calculation in G*Power.

Me:

[JeanetteRichardson-kz]

Thank you so much for this. It really helps me. You go slowly through it explaining it and showing it visually which I need.

[harutohi]

Bless your soul!!! Simple, easy to understand, and to the point! Thank you so much!

[suomiyabao]

Simple and Informative, great video, very helpful. Keep on the good work!

[syedsaadulhassanbukhari]

Hi, How we can calculate participant size when population size is unknown. I want to use chi-square test. I need your guidance. Thank you

[Diana]

the part that confused me was at 13:13 where you go from effect size .5 to effect size the sample size decreased. Shouldn't it be the other way around? Where a larger effect size requires a larger sample size? thank you! :)

[SideeqAli-dq]

Thank you my dear for nice explanation,

[babanthawkar]

Could you please tell me sample size determination for animal study using g power?

[sportethiopia]

Thank you very much; it is something I have been looking for and to informative

[karezkakarash]

Thank you very much for such a great clarification, just Can you let me know how to determine the sample size based on the previous study? I have two group cases and a control

[vaneetgarysandhu]

If I'm comparing TWO groups.... one standard of care (control) and the other intervention... looking at the same outcomes in both groups, would it still be diff between 2 independent means? It isn't matched pairs because it's still technically 2 different groups, right?

[SS-ftvm]

How to calculate sample size for a single group pretest post test experimental design in education? Please help

[carolinesitienei]

How do I calculate the sample size for a four arm RCT.

[adamgarcia]

how do you know a priori the effect size? I am planning to do some experiments and for that I need sample size. Pls comment.

[shakthimala]

Hi how to calculate sample size for a cross sectional study using g power

[shanjohnson]

Hi I could use your help determining a sample size for a research study

[derunbekannte]

How about calculating power within vignette experiments?

[mariolopes]

Hi, can you show how to calculate a sample size for an epidemiological study? Thank you!

[cyrushomes]

Hello Stuart. How about a 3 groups non directional test. We have 25 participants in each group, total of 75 and we would like to run the power analysis. Thanks.

[rravenell]

How do you determine the G Power for Spearman Correlation rho? One group

[pastelqueenwudel]

Hi! Thank you very much for your video! For my homework I have to calculate the sample size for my intervention study (I'm measuring t1 and t2) and I have one control group. So I guess that means I have to use the first way you described? Two independent groups? Or do I have to use another one?