How to calculate p-values

In this StatQuest we learn how to calculate p-values using both discrete data (like coin tosses) and continuous data (like height measurements). At the end, we explain the differences between 1 and 2-sided p-values and why you should avoid 1-sided p-values if possible.

NOTE: This StatQuest assumes that you are already familiar with what p-values are and how to interpret them. If not, check out the quest:
p-values: What they are and how to interpret them.

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0:00 Awesome song and introduction
0:58 p-value for getting two heads
6:39 p-value defined as the sum of three parts
9:30 p-value for getting four heads and 1 tails
12:31 p-values for continuous data, like how tall people are
14:31 A borderline p-value
16:59 A significant p-value
17:47 An insignificant p-value
20:12 One-sided vs two-sided p-values
24:20 Summary of concepts

#statquest #pvalue

[statquest]

NOTE: If you are still wondering why we add rarer events to the p-value, consider this: At the start of the video I got 2 heads and though, "wow! This is special!!!". However, if I got 2 tails, I would have thought the exact same thing. We tend to think that whatever we see is special, even though there are other events that are just as rare, or rarer. Adding them to the p-value compensates for our observational bias.

[MrGolden]

The P-value of this content being normal is less than 0.05, it's super!

[DreamCodeLove]

The p-value that your lectures are special <

[NIHIT]

god gifted or extremely hard working teacher. good to live in the times where such education is freely available.
you are really a gift to the humanity as I believe a lot of people in future will make things (after learning from your videos and not giving up).

[vamanieperumal]

I can't believe how concepts can be made so simple and at the same time so comprehensive. this is mindblowing :)

[papername]

My life would be SO different if I had seen this video 10 years ago. My heart brakes thinking where I could be today and fills me with anger to think that this was simple and my teachers didn't care to teach me and people publishing the class textbooks only cared about impressing their colleagues but never cared about the students. Thank you, Josh. Thank you for bringing this to the world. You're changing lives.

[josephravi]

Triple BAM!!! I learned so much as a teacher from this video. Those classroom learning during my graduating time did not come with this excitement and visuals. So lucid and easy you made it. Not just to understand but also to take away the teaching method -- TRIPLE BAM!!!

[binishrajkhanal]

You should be given a Nobel Prize for all the efforts you put into your illustration guided lectures. I wish I had learnt Statistics from you during my undergrad studies, I would not be scared away and would learn enthusiastically like I am doing right now. Hat’s off to you with immense respect and thanks ❤

[juanaperaita]

This is one of the best explanations I've seen, I can finally understand how the p-value and the hypothesis test works. Thank you so much for your work!!

[elizabethjoy]

Finally happy to realise what the p value actually means. Thank you Josh for all the great efforts to make it so simple and showing that anything complex can be made simple if explained in the way it should be.

[gfocaraccio]

"..and since failing to detect that SuperDrug is making things worse would be bad, one sided p-values are tricky and should be avoided..." .. that final line helped clarify your position on one sided p-values, thank you.

[sanghoonkim]

Ever since my sister highly recommended StatQuest, it has been my favorite Youtube channel since it clears up every concept magically. But the old p-value video still let me confused about what p-value really is... and BAMMM. This video came out! It is fantastic and deserves a million views. Thanks always.

[biplabkar]

I have told this concept to my professor. He was very happy to see this explanation. He is on the list of the top 2% of scientists in the world. But as a statistician, he seeks clarification of the statement that "one-sided p values have the potential to be dangerous".

[joserobertopacheco]

It is extremely rare to find a so comprenhensive explanation like this one.

[somia_ashraf]

After I finished college, I would like to remember when I was studying and listening to these videos, which made things much easier for me and increased my love for the field.

[chasemcdonald]

Oh, my god. I just had the most satisfying aha! moment of my life. What a comprehensive, yet concise, and easy to understand explanation. This deserves more likes, you deserve more subscribers. Incredible content.

[damienhackney]

This deserves a million likes. Brilliant!

[anirbandey]

This is true the best video to understand p-value, not just the statistical implication, but understand it's actual application.

[wesleysbr]

You are incredible josh, and since you mentioned brazil, know that we brazilians see your videos a lot, they are the best, and it's very good that you write what you say in the videos, it helps a lot of non-natives who besides learning statistics still want train english. Your work is commendable, I really appreciate your dedication of time and effort. Thank you very much.

[pkmath]

Nice video! One thing I notice while teaching statistics to students is that many of them are confused between confidence interval and p-value. This video elaborates nicely about what p-value is. As someone who is also teaching statistics, this video inspires me a lot.