Statistical Power, Clearly Explained!!!

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Statistical Power is one of those things that sounds so fancy and, well, "Powerful", but it's actually a really simple concept and this video explains it so it's clear as day.
NOTE: This StatQuest assumes that you are already familiar with p-values and the normal distribution. If not, check out the 'Quests...
p-values: What they are and how to interpret them: • p-values: What they ar...
How to calculate p-values: • How to calculate p-values
The normal distribution: • The Normal Distributio...
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0:00 Awesome song and introduction
0:37 Concepts of Statistical Power
3:19 Definition of Statistical Power
4:57 Overlap and Statistical Power
6:35 Sample size and Statistical Power
7:03 Summary of concepts
#statquest #statistics

Опубликовано:

3 июл 2024

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Комментарии : 306

@statquest 4 года назад

NOTE: This StatQuest was brought to you, in part, by a generous donation from TRIPLE BAM!!! members: M. Scola, N. Thomson, X. Liu, J. Lombana, A. Doss, A. Takeh, J. Butt. Thank you!!!! Support StatQuest by buying my book The StatQuest Illustrated Guide to Machine Learning or a Study Guide or Merch!!! statquest.org/statquest-store/

@ShivamSaini-xt6rg 4 года назад

What tools do you use to make your videos?

@statquest 4 года назад

@@ShivamSaini-xt6rg I use keynote and final cut pro.

@ktburger659 Год назад

I’m watching this and tears are coming to my eyes. So many classes where I felt so dumb. But I just needed it explained a certain way. I can’t thank you enough for your videos, I’m going to share them with everyone I know doing stats

@statquest Год назад

Thank you very much! :)

@appsoftomorrow Год назад

I get it. So true!

@1947umw 24 дня назад

Double BAM!!!

@socratic-programmer 4 года назад

You are a truly gifted teacher. Thanks a lot for this video! I feel like statistics is that much more approachable thanks to this channel :)

@statquest 4 года назад

Wow, thank you!

@datajunkie3427 4 года назад

I have just had a StatQuest Marathon today. You are one of my favourite teachers on RU-vid for knowledge. Thank you sir!

@statquest 4 года назад

Wow, thank you!

@marjiehoss1498 3 года назад

Dang I cant reject the awesomeness of these videos

@statquest 3 года назад

BAM! :)

@1010degreesTIT 3 года назад

I am taking a stat course for my grad school. I am new to this other than one basic stat class in high school. You explained this in a few minutes better than my textbook. Thank you, sir!

@statquest 3 года назад

Glad it was helpful!

@alishahidy848 2 года назад

You explained the concept in a very simple, explicit, and fun way. Thank you.

@statquest 2 года назад

Thank you!

@parttimemusic4629 4 года назад

Omg ! I should have waited and take stats inference course this sem instead of last semester. This video is awesome ! I finally understand power now! Keep the hard work up Josh!

@statquest 4 года назад

Hooray! Thanks!

@ShubhamSingh-ut3nh 4 года назад

You are awesome in every awesome way possible The way you incorporate details of sample size in statistics is so great

@statquest 4 года назад

Thank you so much 😀

@nielsthomsen2324 Год назад

🤡🤡

@Justice_King 2 года назад

Very comprehensive explanation to get the insight even for beginners. At the same time, I also had fun. My heartfelt thanks to you Sir!

@statquest 2 года назад

Thanks!

@del7920 3 года назад

honestly this is the only stat video i was entertained haha and i actually really enjoyed the video and understood everything!

@statquest 3 года назад

Bam!

@tomp9857 3 года назад

Wow, this short video has explained to me what a 2 hour lecture failed to explain! Thankyou so much

@statquest 3 года назад

Glad it was helpful!

@iqbahm 3 года назад

Awsome video. No one else ever explained me so simply what "Power of a study" is.

@statquest 3 года назад

BAM! :)

@katherinenguyen8118 Год назад

bro i could literally watch these videos for fun they're so good

@statquest Год назад

bam! :)

@karolineedrich8628 3 года назад

thank you so much for existing you are literally saving my life

@statquest 3 года назад

Hooray! :)

@suvarnapunalekar4727 4 года назад

I never knew statistics can be so much fun!!! You are a star... thanks for doing this.. :)

@statquest 4 года назад

Thanks so much! :)

@jiangxu3895 4 года назад

Hello there, I have been following your tutorial recently. Great job but far lower sub. for the work you guys have done. Knowledge spread in a intuitive way is invaluable. Thumb up.

@statquest 4 года назад

Thank you very much! :)

@dipeshbansal1396 2 года назад

amazing...each lecture is a treat

@statquest 2 года назад

Than you!

@farsikogama6114 Год назад

Dude, I really want to purchase your book after watching some of your videos!! Great job in explaining

@statquest Год назад

Awesome, thank you!

@edwinadrianta9455 4 года назад

Thank you so much for your amazing explanation. One of the best resources out there

@statquest 4 года назад

Thank you! :)

@feidiqingfay 4 года назад

"Shameless Self Promotion" ... hahahaha ... I can't stop laughing ... so cute ...

@statquest 4 года назад

@pabloignaciomancilla1628 3 года назад

This is fun and truly enjoyable, keep doing it!

@statquest 3 года назад

Thank you! :)

@alecvan7143 4 года назад

Love the sound effects

@alecvan7143 4 года назад

Yet another topic I just figured I'd never get so simply and logically explained. Thank you, Josh.

@statquest 4 года назад

Hooray!!! :)

@Quijanos1 3 года назад

Excellent explanation of Power; this was helpful. Thank you.

@statquest 3 года назад

Glad it was helpful!

@RadicalVideos 4 года назад

Very helpful and with comedic relief. Thank you so much

@statquest 4 года назад

Bam! :)

@avam.212 Год назад

Oh wow, I didn’t expect the example problem to be the exact one I was looking for!!!

@statquest Год назад

bam!

@yangwang6805 4 года назад

Finally understand what is power, thank you for your wonderful video!

@statquest 4 года назад

Hooray! :)

@michellenamuyaba5558 3 года назад

This is amazing! In just 8 minutes! thank you❤️

@statquest 3 года назад

Glad you liked it!!

@saneeshcs6604 2 года назад

Last week my professor told me that we don't power to explain a result. I wondered the powerful one in the group says we don't have power. That powerlessness took me here. Thanks a lot for explaining power so clearly. She (professor) is powerful again, because she understood it. Thanks again.

@statquest 2 года назад

bam!

@vanilla__latte 2 года назад

This is the best stats channel on RU-vid

@statquest 2 года назад

Thank you! :)

@zinnijha7556 2 года назад

Thank you !! For simplifying for the rest of us.

@statquest 2 года назад

Thanks!

@infinger2006 Месяц назад

I guess I'll have to watch the next video to see the difference between adding more samples to gat more power and the dreaded P-Hacking... on to the next video!! Thanks for the videos..

@statquest Месяц назад

bam! :)

@MediocreCumLaude 9 месяцев назад

College courses are so hard for me because professors try to talk in PhD-ese. Thank you for breaking it down in simple terms.

@statquest 9 месяцев назад

Glad it was helpful!

@apoorvarawat2235 Год назад

I love the way you teach..... But honestly I love your opening! "There's clouds outside... But who cares.... It's time for Stat Quest... STATQUEST... "

@statquest Год назад

Ha! I'd forgotten about this tune. It's a good one. :)

@apoorvarawat2235 Год назад

@@statquest thank you so much for your reply.... U r too good to be true♥️

@clairefontaa587 4 года назад

Thank you for the great content again! Do you plan on making a video on Cohen's d, Cochrane's Q and all those meta-analysis merriments one day? :D (desperate PhD student asking)

@marcelsa5191 2 года назад

Thanks for the strong video! Cheers from Ox.

@statquest 2 года назад

Thank you!

@tina9753 2 года назад

♥ what a wonderful video! not even comparable to my dry epidemiology classes...

@statquest 2 года назад

Wow, thank you!

@gowthammurali1224 2 года назад

From this video i get to know that increase in power will decrease the type 1 error. May i right Mr.jos.. What a intutive video man...salute for your knowledge sharing....

@statquest 2 года назад

Thanks!

@lizaminasyan9255 2 года назад

thank you so much for this fun video

@statquest 2 года назад

Glad you enjoyed it!

@aziausa 3 года назад

I feel I am out of words that will fit in your appreciation. You are simply amazing !!!!! Thank you so much and keep these gems coming, please. Can you please explain what is Tukey HSD analysis and how do we perform that?

@statquest 3 года назад

Thanks, and I'll keep that topic in mind.

@rkperohindirich6824 Год назад

Amazing content! MANY MANY THANKS ❤❤❤❤❤

@statquest Год назад

Most welcome 😊

@rimkenan4654 Год назад

This is so helpful thank you so much! 🙏🏽✨ Greetings from Belgium 🇧🇪☺️

@statquest Год назад

Thanks and greetings from Spain! (I'm in spain for the next week for work).

@annawoodard6457 2 года назад

Thank you for your great videos!

@statquest 2 года назад

Thank you so much for your support!!! :)

@sarasorrell8476 3 года назад

This is amazing. Thank you so much!

@statquest 3 года назад

Glad it was helpful!

@MiguelDimase 2 года назад

I never saw an author answer every question or acknowledge every comment; it's remarkable (and I'm not saying you HAVE TO do it; it's a huge job. I think it takes more time than making the videos themselves! -which, by the way, are excellent-)

@statquest 2 года назад

BAM! :)

@karducito22 2 года назад

Man you are awesome! I hope some day ! will teach like you

@statquest 2 года назад

Thank you!

@maggiehuang5566 9 месяцев назад

When you are driving in the rain, you can kinda see where you are going(how I felt about statistics before your video), the wind shield wiper is still necessary because it makes everything clearer (that's how your videos are to me). Confession: I was rolling my eyes when the cheesy BAM!!!s came out.

@statquest 9 месяцев назад

bam! :)

@stum5033 7 месяцев назад

Great video thank you!

@statquest 7 месяцев назад

Thanks!

@adriancruzat6994 3 года назад

I hate that I'm finding out about this channel so late. My test is tomorrow and watching your videos would've helped so much. Nonetheless, I'll be binging these videos all night haha

@statquest 3 года назад

Good luck on your test! :)

@adriancruzat6994 3 года назад

@@statquest thank you!

@JavierSegoviaHernaez-mn8uy Год назад

So goood. Muchas gracias desde España !!

@statquest Год назад

De nada! :)

@nancyanderson5413 Год назад

LOVE YOUR VIDEOS, BAM!!!

@statquest Год назад

Glad you like them!

@ashleyslater8880 3 года назад

So helpful!

@statquest 3 года назад

Thanks!

@amritadayal1939 4 года назад

Hi... Me and my husband really likes your videos... Your explaining skills are great and things become simple to understand... Please upload some videos related to Natural Language Programming

@statquest 4 года назад

Will try

@SemicolonExpected 2 года назад

I fully expected to hear "AND SUBSTITUTE MY OWN" after you said "I REJECT YOUR HYPOTHESIS"

@statquest 2 года назад

@anna56887 3 года назад

The varieties of BAMs got me 😂😂😂😂😂 Thanks for this video . Really helped me understand the concept

@statquest 3 года назад

Hooray! :)

@navishdavid2327 10 месяцев назад

Thank you so much for This

@statquest 10 месяцев назад

Thanks!

@NastroArzurro 2 года назад

Thanks so much!

@statquest 2 года назад

You bet!

@luisrodrigueziii7316 Год назад

YOU ARE THE GREATEST

@statquest Год назад

Thank you! :)

@dsavkay 2 года назад

Thank you!

@statquest 2 года назад

You're welcome!

@yisheng1084 3 года назад

Really clear

@statquest 3 года назад

Thanks!

@funnygasim1281 2 года назад

I literally love you

@statquest 2 года назад

@TheVideosSalo 3 года назад

Most fun statistics i've had!! BAMMM

@statquest 3 года назад

BAM! :)

@danai.ch9 3 года назад

thank you so so so much

@statquest 3 года назад

You're welcome!

@Wagdimg12 2 года назад

Thanks!

@statquest 2 года назад

Wow! Thank you so much for supporting StatQuest! BAM! :)

@dr.battulapradeep1183 3 года назад

The P value by seeing....

@statquest 3 года назад

bam! :)

@arimorrison7816 3 года назад

When the Null Hypothesis says "subscribe to my channel for more stat videos," my small p-value says "I will continue to watch your videos without subscribing!" MEDIUM BAM

@statquest 3 года назад

Noted

@user-bz8nm6eb6g 2 года назад

Love it!

@statquest 2 года назад

@chicagogirl9862 Год назад

I love the song in beginning of videos:)

@statquest Год назад

Hooray! :)

@mostinho7 2 года назад

3:15, 7:00 for great summary (doesn’t miss anything from the video)

@statquest 2 года назад

Yep!

@sarthakdev6025 4 года назад

Please do a video on "maximum mean discrepancy"

@CandyLin0401 8 месяцев назад

Laugh upon hearing there's a shameless self promotion LOL Good job!

@statquest 8 месяцев назад

Thank you! :)

@aditigupta2803 8 месяцев назад

@statquest Can u pls make a video explaining concepts of stationarity and consistency in time series? And also the difference between weak and strong law of large numbers? Will be really helpful☺

@fatimaq884 2 года назад

You're the best !!!!!

@statquest 2 года назад

Thanks!

@ekenechikwelu3790 3 года назад

thank you so much stat quest, i am currently doing a master thesis on TOST and using Assurance in place of power to calculate sample size, my background is clinical medicine, have little knowledge on stat, but thanks to your video i am doing fine in stat. However pls, i have a request, can you make a video on the concept of Assurance, or refer me to resources to help me on this subject.. Thanks

@statquest 3 года назад

I'll keep that in mind, but I can not promise anything soon.

@carlosp.6968 3 года назад

great video!!!

@statquest 3 года назад

Thank you! :)

@Gengar99 2 года назад

You're an angel.

@statquest 2 года назад

Thanks!

@haydennelson2115 Год назад

My new favorite video ^^^

@statquest Год назад

bam! :)

@vladfarias 4 года назад

It is just perfect!!!!!!!

@statquest 4 года назад

Thank you! :)

@dhanush5247 4 года назад

liking and commenting before watching

@statquest 4 года назад

BAM! :)

@amanzano65 5 месяцев назад

Bam!!!!! this video is great

@statquest 5 месяцев назад

Thank you!

@marlenetaveras9780 3 года назад

love the humor!

@statquest 3 года назад

Thanks!

@shubhamtalks9718 4 года назад

Please make a video on t-dist .

@googledude5649 3 года назад

Much power in the lol - so good man

@statquest 3 года назад

Thanks! :)

@nupentin Год назад

I LOVE YOU SO MUCH

@statquest Год назад

@giorgiosperandio8708 Год назад

Thumb up for the intro

@statquest Год назад

BAM! :)

@haneulkim4902 2 года назад

Thanks for an amazing video! One question, if I want to prove that data selected from two different group actually comes from the same distribution(opposite of your example) than do I need to set new null hypothesis("data come from different distribution") or does not rejecting null hypothesis multiple times prove that datas come from same distribution?

@statquest 2 года назад

Unfortunately you can't turn the hypothesis around. For details, see: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-0oc49DyA3hU.html

@sukieyakie 3 года назад

could you help me with this? i am assigned an experiment with growing of mung beans in seasalt vs sodium chloride (table salt) and my null hypothesis for the experiment is that there is no difference in growth whether it is grown in seasalt or nacl. my alternate hypothesis is that there is a difference. however, before i start the experiment i need to find out the number of beans to use for each test i.e n=? and to find out the optimum sample size to use, my teacher asked me what is the statistical power for this experiment? please help ive been stuck on this for days and cant start my experiment because i still cant justify the amount of beans i should use to test on.

@statquest 3 года назад

Umm... Just follow the steps in this video to calculate the sample size.

@mohammedelhamamsy3275 2 года назад

Beautiful explanation, Thanks a lot! There's only one thing that I still find confusing that is: if the two distributions highly overlap with each other, what prevents us from thinking that both come from the same distribution? I mean we are looking at the weights of the exact same species (mice) why did we have a priori assumption that the weights of those on the special diet are different from those on a normal diet?

@statquest 2 года назад

If we have no reason to think that the mice come from two distributions, then we would not spend the time and money testing the hypothesis to begin with. So, in this case, we must know something about the diet - maybe one is very unhealthy, and the other one is very healthy - and this causes us to suspect that they might be from different distributions, and this then justifies spending the time and money doing the experiment and testing the hypothesis.

@mohammedelhamamsy3275 2 года назад

@@statquest Got it, Thanks again ❤

@pradeepkumar-ew1ze 3 года назад

Going by these videos and your Linear Regression videos, I wonder how many mice you got as Pets :)

@statquest 3 года назад

I used to work in a laboratory that studied mouse genetics.

@stephennguyen8052 2 года назад

Hey Josh, thanks for the video! In the event that you truly have one distribution (4:17), what if you sampled data from the 2 tails and do hypothesis testing, isn't it possible to falsely reject the null hypothesis? Why is it that power doesn't apply in that scenario?

@statquest 2 года назад

Yes, it is entirely possible to falsely reject the null hypothesis. This is called a "false positive" and it is controlled by the threshold of significance you set for the p-value. So you control false positives with the p-value. In contrast, you control false negatives with power.

@constantinp6488 4 месяца назад

@statquest man, you should create courses for Data Camp since they pretty much suck in explaining difficult statistical things :)

@statquest 4 месяца назад

I'll keep that in mind!

@chinmaypotdar9358 3 года назад

Omg you sing so well :)

@statquest 3 года назад

@benwilde1768 4 года назад

Will you do a series on multilevel models (aka linear mixed models or hierarchical models)?

@statquest 4 года назад

It's on the to-do list.

@karthica5251 6 месяцев назад

Out of curiosity, at 2.13 even though we are knowingly calculating the p-values from samples from 2 distributions, do we still apply the BH method (FDR) discussed in the previous stat quest? When do we use FDR?

@statquest 6 месяцев назад

When you know that you have two distributions to begin with, there's no point in even calculating the p-value to begin with. In other words, this is just an example. That being said, in practice, we never know, and if we do multiple tests, then we should correct for that with FDR or some other method.

@nupentin Год назад

Awesome

@statquest Год назад

Thanks!

@varadgunjal 2 года назад

Beautiful video! Any chance we can access the slides for quick revision @JoshStarmer ?

@statquest 2 года назад

I have PDFs of some of my videos here: statquest.org/studyguides/ and have a book coming out soon.

@noname-go2kt 5 месяцев назад

Hi,your videos are great,and the opening sequences as well,thanks a lot My question is, what do I do if I want the power but at the same time don't know if my null hypothesis is true or not

@statquest 5 месяцев назад

You never know about the null in advance. You just calculate power based on the assumptions that the two things are different and by so much. So, given those assumptions, you can calculate power. We then do the test and, if there is a difference, we should be able to detect it and reject the null.. If not, then we'll just fail to reject the null.

@noname-go2kt 5 месяцев назад

@statquest I am sorry I don't understand what do you mean by the two things.For example at 4:25 you have said that the concept of power doesn't apply here since we know beforehand if our null hypothesis is correct or not. However what if I don't know,in short,is there any situation ever where I should not calculate power when doing hypothesis testing? Thanks a lot in advance

@statquest 5 месяцев назад

@@noname-go2kt Yes, when we know that there is no difference, then Power does not apply. But we never know - otherwise we wouldn't bother doing the test to begin with. So we assume that there is a difference and carry on from there. In theory you should always do a power analysis if you have reason to believe you need to do a statistical test.

@jiaming5269 4 года назад

u r amazing...

@statquest 4 года назад

Thank you! :)

@casualcasual1234 2 года назад

Thanks a lot and I would like to ask: at 4:23, if 2 distributions are the same then there is no need for power so no Power analysis. However, I think we do power analysis to find optimum sample size and then do tests to see whether special and normal diets have 2 different distributions or the same. So may I ask won't this be a contradiction?

@statquest 2 года назад

We simply assume that we have two different distributions.

@casualcasual1234 2 года назад

@@statquest Oh thanks.

@MM-qk8eg 2 года назад

based on this video, I assumed that independent samples t-test should have more power than paired-samples t-test. But apparently, that is incorrect: "When the same participants are used across conditions, the unsystematic variance (often called the error variance) is reduced dramatically, making it easier to detect any systematic variance". could you help me with this? Thanks!

@statquest 2 года назад

If your samples are paired, then you should use a paired t-test (and it will have much more power than unpaired), this is because pair samples tend to have some correlation, and that information is helpful in understanding how different things are.