Power & Effect Size 

Amazing video, i would recommend this to anyone in search of a basic and concise explanation.

You are insanely good at explaining concepts, best regards from Colombia, South America.

i like how clearly you explain those concepts! Please do more if you can

Absolutely the best! Please keep it up. Thank you!

This is my new favourite video on youtube! I've bene struggling to get these concepts right for so long - you've put them in such a clear and logical way! Thank you so much!!

You have saved my Research dissertation!

Thank you so much! This has been extremely helpful.

Very clear and compact explanation. Thanks.

Hi Courtney, I recently shared your video with a statistics class that I'm currently taking because your explanation of the concepts is very good! However, I was told by my professor that in 6 minutes 13 seconds of the video the effect size of ANOVA use eta was indicated, but it should be eta squared. Again, your explanation of the concepts impacted my understanding to the degree that I shared the video with my class! Therefore, great job and thank you for the clarity of the concepts!!!

I've been doing Monte Carlo methods to estimate power of studies that are already published but did not report power. I don't see that as a waste of time because it helps me evaluate whether the study was likely to have missed an effect that other studies detected due to low power.

Best one that has described effect size ty

thanks for this. very clear. cheers from a romanian studying in the Netherlands :)

R square and Cohen's d has the opposite spectrum when they come to indicating effect size, where R square is negatively related to effect size, and Cohen's d is quite positively related.

Many thanks from Uganda-East Africa

Nice explanation! And also a nice pace of speech :)

What if we don’t have the effect size (no previous studies available)?

Its awesome 🥰. thanks. Pls Do more useful, interesting videos.

There might be a small mistake in one of the slides. At <a href="#" class="seekto" data-time="360">6:00</a>, first it's written as Cohen's "d" for small and then switches to (Pearson's ) "r" for medium and large. Thank you! Have my "Like"

Fab video. Thank you.

Thank you very much for that incredible video!! very helpful !

thanks so much! this was super helpful!

Nice explanation and voice.

Courtney: Is there a pdf of these slides, I would like to print them. Thanks for uploading/sharing :)

thanks, both adding clarity and covering a broad area.... 🙂

good explanation, thanks!

This helped me alot, thanxs! thumps up!

excellent explanation thank you

Thank you!

Thanks for this video!

When calculating the effect size do you use the number of participants enrolled or the intent to treat population numbers? For example there were 53 patients randomized to receive treatment X however two of those patients were exluded because of an incomplete baseline assessent. Do I use the number of patients initially enrolled (53) or the number of patients (51) after exclusion?

Thank you so much

thanks a lot!!!

Good

I don't get it. How do you compute power BEFORE you do the study? I cannot compute p-values for example without my data (since I can't compute the mean). Therefore, how do I actually compute the power before the study starts (before I collect data)? Is it just with simulated data and then using that and estimates of the means, stds, guess a sample size that is needed?

its fun to say your last name

Power & Effect Size

no voice ???

I would like to marry you. Thank you!

I suggest to please speak a little slower so that everyone one could follow, particularly those whose first language is not English.

this video is very helpful. appreciate it!

Thank you!