13 - ANOVA Basics - The Grand Mean
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- เผยแพร่เมื่อ 21 ก.ค. 2024
- Get more lessons like this at www.MathTutorDVD.com.
In this lesson, we will continue the study of Analysis of Variance (ANOVA) by discussing each part of the calculation separately. Here we discuss the grand mean, which relates the mean of all of the sample means in the data sets.
This will then tie into the sum of squares among treatments and sum of squares of errors in the final ANOVA calculation.
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This Professor is the best. He is able to make reasoning very simple!!! I love him!!!
After this tutorial I felt dumb for not understanding this in class…this video is legendary it’s basically ANOVA in it’s simplest form
Thank you so much!
Thank you so much you have successfully improved my understanding of The Grand Mean! I love your teaching style and how you clearly explain what you're referring to and what it does and how it does it! This video is an absolute 'must-watch' for all students doing statistics!
He will repeat in detail as many times as necessary to make sure that you understood every single thing of each lesson. This is what makes him quite unique among all the courses I've studied. Awesome professor!🤩
This is amazing. I love how you took your time to explain it bit by bit, like we are all Statistic dummies😅...Thank you so much!
😂
You guys are just the best !!! Am learning in french but statistics just feels like another language to me but when ever i watched your vidéos, the concept becomes just clear.thank you so much.
Very happy to help!
Thanks for your explanation I'm MSc student and I'll use them very much next months because this technique is modern more than other statistical techniques
This dude is the man... going through every single step one-by-one... he should be getting paid for that.
At over 800k subscribers, I assure you, he is.
Great video and explanations.
One comment: the mean of all the data points will only be equal to the mean of sample means if the sample size numbers are equal.
this.
Is there an immediate follow-on lesson that picks up where this one left off? I can't find it among the videos posted by "
Math and Science"
thank you so much, I am starting to understand what is going on
Thanks.......... the equation has always scared me away but they are simple once you know. Thanks again!
love, love, love your explanation. you made it so easy... thank you so much.
Is there any way you can make your videos populate in consecutive order? I love you videos but I spend time trying to find the next video. Great explanations!! Thank you so much, i am listening
The whole series are on his website and he wants you to buy his videos from his website.
What should happen if the sample sizes are different?
what if there a different sample size how to compute the grand mean
What if the sample sizes are different? Is the grand mean still the mean of the sample means, or would you add all the data values and divide by the total number of readings?
Good point. If the sample sizes are different, then the mean of sample means is *not* the same as the mean of all readings.
What test is he referring to when he says that another test aside from ANOVA should be used to identify which mean is different?
whats about the standard deviation of the grand mean?
Great explanation, much appreciated! 👍
You're such a great teacher!
Hi, you are not supposed to refer to"j" as the 'jth' sample. The 'i' represents the sample but the 'j' represents the observation.
Please when is the next video on Anova dropping?
when samples are different in size. then how we use grand mean?
using ANOVA approaches calculate the sample standard deviation when the sample sizes are 100, 100, 100 and 100 and the sample mean are 3.85, 2.55, 2.8 and 2.78
Is lesson # 14 available here?
Thanks so much for this detailed explanation on ANOVA!
Thanks for the video. Very comprehensive.
Hi, can you please share the link to the following lesson?
Great video, but you should keep apart these two characterizations of "grand mean": (1) Mean of all individuals combined and (2) Mean of the sample means. (1) is always true (by definition), but (2) only coincides with (1), if all samples have the same size.
Was this the last video in stats volume 7? I can't locate the rest of the videos
Thanks so kindly. How do I get the next lesson?
can any one help me to get the other videos related to ANOVA explanation? the other videos in this series ?
But the average of sample means is not equal to the grand mean if sample sizes are not the same for all populations being compared, is it?
You are a good teacher
A better question would be:
"Why is Texas letting girls get married at 13 years old"?
Victor Drew 😂😂🤓🤓
I also noticed that
I'm from middle east, I see these things happening in my society and hate all of these kinds of marriages 🤮🤮🤮🤮
Suddenly I see the same shit in USA !!!!🧐🧐🧐
Lol... Good question!
Because Texas is almost Mexico 🇲🇽 (it was) haha Xd
and also not a single one of them is over 23 yrs old and the grand average of all of them is 19 and a half yrs old aka the grand mean shows that all these states have females getting married when they're still TEENAGERS, lol wtf?
this is the second video of yours i've watched and i think i'm ready to die for you
If you take the mean of the sample means, when sample size is different, the value will be different. (Weighted average). The grand mean just sums up all values divided by total number of values.
How did we get i to be equal to 1?
What is i actaually?
Thank you so much for your videos 🙏🏽🙏🏽🙏🏽
Legend
Tq sir... u make statistics sound simple
link for next video after this please
But your videos are great, tommorow is my exams and youre helping a lot
around time 5::27 he says that the mean of the sample means, is the mean of all the data in the samples. This is correct only if the sample sizes are the same, (just as in his example), but not in general.
Interesting. as for ANOVA it seems that the ANOVA calculates the weighted mean of the sample means, and it is really a mean of all the sample.
@@uzipaz9557 so he was correct?
The video is very helpful.
hello sir. why you divided by 30? the sample mean is always N-1. So you need to subtract the grand total by 27?
Yes, we should devide by 27
@@chiruvlogss No not in this case, it's just the mean of all the values
A very good review in stats for me
What is the next video after this one? I can't find it? It's not "14 ANOVA Basics" !!
Can you just add up all the means from each individual sample then just divide by 3?
Liam Howard That only works if all the groups are the same size.
woodchuk1 Aren’t they? There are ten numbers in each column. That’s what you mean right? No pun intended
Liam Howard Yes, that’s what I meant, that in this case you would be correct...but in general, if the groups aren’t all equal, the mean of the individual group means won’t equal the grand overall mean.
woodchuk1 I see. I actually thought that’s what you were saying right after I hit the send button.
At 7:08, the lower sigma should be over the range i=1 to k or the summation is undefined and makes no sense.
excellent explanation
"Grand mean is the mean of sample means." but what if sample sizes are different?
This should be the question (:)
big big thanks for that❤
A sample from Texas marries at age 13? I think you got the wrong state?
Thank you!
Thank you Man..
that is really good
Very helpful
Thank you sir
Dear PhD Math and Science, you explain really good. Thank you
Your explanation seems a bit misleading: the mean of means is only equal to the mean of all the data if the samples have the same size. Of course, with the formula later it‘s clear, that this is taken into account.
Mean of means and mean calculation of all 30 case , 10 each , is different thing . The tutor started by saying that if one averages mean of group 1,2,3 can get grand mean. It's not true. Grand mean is mean of 30 samples
Thank you 💕
Thank you so much
Hiii
thank you
I was lost ...I was looking for the grand mean calculation only. Quit 3/4 thru.
Great
We need part 14 plssssss
th-cam.com/video/mSELslrWdS4/w-d-xo.html
What does i stand for?
the last data for Texas is "13", unbelievable
I wonder why I didn't know that my Prof gets data from here
When you start a subject you Must finish it !!!!!
Where is the continuation 14 -?
its for sell dumbass
5:30 grand mean is the average of all the samples...
what if the sample sizes are different
edit: nvm the formula after make sense. i was think something else
Before doing the grand mean, just estimate means for each case and sum up them then divide it by the number of sample means. you have three means (n=3). I think this helps.
@@user-ik2tk7xi3g forgot the context. i was wondering what happens if we have samples of different sizes. like
sample-1 = {100}
sample-2 = {0, 0, 0, 0}
sample mean of sample-1 = 100
sample mean of sample-2 = 0
sum of sample means = 100. divide that by 2 and we get 50
BUT that's not the same as aggregating all samples into one big one and computing its mean
sample-1+2 = {100, 0, 0, 0, 0}
sample mean = 100 / 5 = 20
@@marcuschiu8615 well, that is good point. Based on my knowledge, if we represent our sample value as 0, like you mentioned it, I don't think its counted as a value and the grand mean be exactly the same with the sample of the first one. STATA , SPSS and other statistical applications count these data's as a dummy variable and counting it as a zero value. If it's coding , like using R-studio and we represent that zero value, then the result might differ. Just my thoughts. Thanks thou for your insights
I asked myself the same question. I believe the video, when introduced the term "Grand Mean", implied that the sample sizes are all the same without explicitly stating it. According to Wikipedia, "The grand mean or pooled mean is the mean of the means of several subsamples, as long as the subsamples have the same number of data points."
en.wikipedia.org/wiki/Grand_mean
ur a god
Wouldn't it be wonderful if we just add up all the values and divide them by the total. Geez!
Or just sum the 3 means from the samples and divide the result by 3!
JuanFernando Gracia doing this gave me a different result
Wow
Thank you for your explanation but in what year did girls in Texas get married at 13 lol?
22/12/2022
Nice!
@@MathAndScience what a waste of time since there is no next video on this topic
Dang...baby girl got married at 13 in Texas...ugh. I hope this is fake data!
You r ryt you should have skipped 90% of the things u said in this lesson 😒😒😒gosh! Its part 2 nd u hvnt started calculating ANOVA!
You are “texist“. Why is the youngest girl to marry in Texas?
sorry I CAN'T MAKE SENSE
Making it long without informative material
Please hindi language in speaking
I don't care WHY you are making choices, just get on with the procedures!
Maybe you should care why, so you get more than a surface understanding.
Why take all this time explain grand mean?
basically you add all the numbers in all the groups together n divide by the total number of ppl video couldve have been 3 mins instead of fuckin 20 mins smh
Too repetitive and talks to much, just do and say
That noise that comes from the mouth like eating st. .. distracts