THANK YOU SO MUCH! I literally spent five hours reading articles and statistics pages that did no more than confuse me and watching your video was so nice and relaxing for me because not only were you clear but you were able to explain it with a useful example
I don't know why I was having so much trouble understanding this test with written direction but your video was very helpful to me. It presented the necessary info concisely and in a manner east to understand.
Thank you so much for posting these videos. I keep running into explanations with shortcuts because calculators usually do the work now, but I get stuck on the details. Wish I had you as a teacher in high school!
Thank you very much for your videos! By writing down the statistical tests it is easier to understand and you explain it very well, slowly and in a very clear way !
Thank you so much! I'm taking an online class, and they never mentioned how to do the ranking, so I've always been really confused at how the answer was gotten.
Once again, thanks for the assist : ) This was an awesome and useful video for me. I am great with the parametric statistical methods, but one of the college students that I tutor had questions about non-parametric students. Great explanation!
Amazing!! I am studying for the 6-sigma black belt exams and this made me understand the Mann Whitney U test. I have subscribed as your explanations even for the Kruskal-Wallis test was equally very clear!
Great explanation! my module provided an Excel spread sheet to do this, on which it said they expect us to also do it by hand but they didn't explained how. Thanks for the help!
Thank you for that immensely helpful video. I have a small clarification question. Let's say there are three scores that tie, does the procedure of calculating the average apply as well? That is, if you had three 2's among your scores, would each get rank 2 by (1+2+3)/3=2?
this video is excellent, thanks! I have a small sample size and R couldn't deal with all the tied values, was able to do it myself in 15 mins following this.
Why is the U value being calculated differently in this example? The original paper by Mann-Whitney 1947 uses a different formula. You are also not the only professor I have seen using a different formula.
Two questions - 1. Why did you take U statistic instead of Z for comparing calculated and critical values ? 2. U statistic is calculated with the formulae : U1 = n1n2 + n1(n1+1)/2 - Sigma R U2 = n1n2 + n2(n2+1)/2 - Sigma R your formula for U-statistic is different. I could not find that in any statistic book or internet. All of them give the listed above formula. would appreciate if you could answer that. Thanks, Bhaskar
The formula is different, but the values calculated for U1 and U2 are just exchanged. This is because the above formula just subtracts the formula used in the video from n1n2. In the end while selecting the min(U1,U2) it wouldn’t matter if the values of U1 and U2 are exchanged. But still, I wonder why change the formula anyway.
According to Wikipedia Ua+Ub should equal Na*Nb. in my data set i have 2 groups for a total of 126 responses. Na=67 Nb=59. Responses range between 0 and 10 in their value. Group A has: 17 responses of 0 ranked at 11.5 3 responses of 1 ranked at 26 4 responses of 2 ranked at 33 5 respoonses of 3 ranked at 44 6 responses of 4 ranked at 55.5 20 responses of 5 ranked at 78.5 2 responses of 6 ranked at 99 3 responses of 7 ranked at 103 2 responses of 8 ranked at 110 0 responses of 9 and 5 responses of 10 ranked at 120.5 Group B has 5 responses of 0 ranked at 11.5 4 responses of 1 ranked at 26 3 responses of 2 ranked at 33 10 responses of 3 ranked at 44 2 responses of 4 ranked at 55.5 18 responses of 5 ranked at 78.5 1 responses of 6 ranked at 99 2 responses of 7 ranked at 103 7 responses of 8 ranked at 110 0 responses of 9 and 7 responses of 10 ranked at 120.5 So I calculated my Ua and Ub and tried to check whether I did it right, However, when i add Ua and Ub i get 3985, whilst Na*Nb amounts to 3953. So i must be doing something wrong. I have no clue what. Does anyone have any clue what is going wrong?
Happens almost fail-proof. You calculate something wrong, and you know it is but not why... as soon as you start panicking and flailing around until you give up and ask others for help you see your mistake...., Mine was that i calculated the U's wrong. I did Ua= Ra-((Na(Nb+1)/2) instead of Ua=Ra-((Na(Na+1)/2)..... Aaaanyway thanks a bunch for the vid, also helped me alot. Cheers from the Netherlands!
The explanation was very clear, thank you for sharing it. I would like to make a suggestion - include a slightly more elaborate example that connects these numbers to the real world. In this case you mentioned that the numbers came from the results of two distinct treatments. For me it would be more helpful if that was accompanied by something like "The numbers you see correspond to the number of lesions that remained on a person's body after treatment was applied; thus we want to compare the lesion-healing effects of drug A and drug B". This would make the problem less abstract. Otherwise there is a chance that some people will be able to do the number-crunching, but struggle to come up with an answer when asked "so where can you apply this?".
Mr. Eugene if you are a class teacher and you conduct exams for two different classes but in the subject. mathematics two data is different in number one class is 32 and one class is 14. they are both skewed. con you please use this approach to compare the performances between theses classes?
This is the day before my exam and let's just say you turned a 1hr class into 9 min! Thank You!!!
Day of exam💪💪
@@VaporyBeathow did it go
The best video I have found regarding the Mann Whitney U test! Thank you!
Once again, clear, right to the point, easy to understand, only 10 minutes. Thank you for your work!
I'm doing a Thesis for the Dentistry Degree in Italy and you saved me! God Bless You, man!
THANK YOU SO MUCH! I literally spent five hours reading articles and statistics pages that did no more than confuse me and watching your video was so nice and relaxing for me because not only were you clear but you were able to explain it with a useful example
Thank you so much! My exam is tomorrow and I just spent all day stressing over this and I am so glad I found this video!
My 1 hour tutorial that had no favorable outcome had been solved in 9 minutes. Thank you, great job.
U just turned a 2 and a half hour lesson into 9 mins and I learnt way faster thank you
I'm currently writing my dissertation and this was immensely helpful - THANK YOU!
You're a legend. I am embarrassed to say how long I spent trying to figure this out before i watched this video. Thank you.
I don't know why I was having so much trouble understanding this test with written direction but your video was very helpful to me. It presented the necessary info concisely and in a manner east to understand.
I don't have to perform it by hand but your explanation helped me understand what I'm "clicking" in Statistica. That was so helpful, thank you.
You just saved my classes bacon on their psychology coursework, Thank you!
Mr. O'Loughlin, you are my hero. Thank you so much!!
Thank you so much for posting these videos. I keep running into explanations with shortcuts because calculators usually do the work now, but I get stuck on the details. Wish I had you as a teacher in high school!
Thank you very much for your videos! By writing down the statistical tests it is easier to understand and you explain it very well, slowly and in a very clear way !
Thank you sir , this video has cleared all my doubts which my university teachers couldn't solved!
This man is out here saving lives.
Thank you so much! I'm taking an online class, and they never mentioned how to do the ranking, so I've always been really confused at how the answer was gotten.
Thanx proffessor u save my life today bcz tomorrow I have exam but bcz of this video everything is fine now thank u so much😍
The best video on TH-cam for mann Whitney u test
Well done Eugene on another great video. Clear and concise as always. Please keep up the good work
Once again, thanks for the assist : ) This was an awesome and useful video for me. I am great with the parametric statistical methods, but one of the college students that I tutor had questions about non-parametric students. Great explanation!
I'm taking Stats online and I only have my book to guide me step by step and this video helped so much! Thank you!
thank you so much for this. your video series is so clear and concise. you are a legend sir
Amazing!! I am studying for the 6-sigma black belt exams and this made me understand the Mann Whitney U test. I have subscribed as your explanations even for the Kruskal-Wallis test was equally very clear!
I was confused about the last bit, thanks for clearing!
Watching this 1hr before exam :). Thx
Thanku so much! Tomorrow is my exam and your video is so helpful ❤
Great video, everything is explained simple and steb by step. Thank you!
Thank u for being a genuine life saver...like I can't even express how much you have just helped me THANKYOU!!!!
Great explanation! my module provided an Excel spread sheet to do this, on which it said they expect us to also do it by hand but they didn't explained how. Thanks for the help!
Amazing video. It's essentialy one of my statistic lectures in a fraction of the time.
Keep up the good work!
I've got an exam after 4 days and thanks your video
Very simplified and well explained. Thank you
This was extremely helpful! Very clear, simple, easy to understand explanation.
Thank you!!!! This video made everything sound so simple!! Saved my grade!!
Thank you for that immensely helpful video. I have a small clarification question. Let's say there are three scores that tie, does the procedure of calculating the average apply as well? That is, if you had three 2's among your scores, would each get rank 2 by (1+2+3)/3=2?
Yes. 😊
wow, i wish my stats teacher was as good at teaching as you are
this was super helpful!! thank you for taking your time to do this im so grateful!!!
Thank you for your very clear and helpful explanation.
Thanks God I met your video! You're an ANGEL!!!
You're the best sir. Take a bow.
Thanks a ton. Please keep making videos on stats and enlighten us through knowledge.
this video is excellent, thanks! I have a small sample size and R couldn't deal with all the tied values, was able to do it myself in 15 mins following this.
You are amazing! Best video for exams EVER! Thank you so so much!!!
Excellent work sir. Understood it in a single watch.
Great Sir, very simply you taught it, I felt like I learned it in a class.
Hi, please can you do a video on Wilcoxon signed rank test?
thanks so much my exam was is today and i missed the lectures on this saved me
I am finding your videos very helpful! Thank you for sharing your knowledge!
But I think the h stastic falls in the acceptance region when represented in a skewness how comes we're rejecting the null hypothesis
Love your videos, please keep making them. I have learned loads =)
Beautiful, instructive example sir!
Exceedingly well explained
But for a two tailed test , you are supposed to use the higher u calculated value, right??!! so is this a slight error ?
What pen do you use for writing..it is so neat and legible! Needless to say your explanations are on-point!
Thank you very much! It was a big help for me. You save my assignment.God bless.
Why is the U value being calculated differently in this example? The original paper by Mann-Whitney 1947 uses a different formula. You are also not the only professor I have seen using a different formula.
Two questions -
1. Why did you take U statistic instead of Z for comparing calculated and critical values ?
2. U statistic is calculated with the formulae :
U1 = n1n2 + n1(n1+1)/2 - Sigma R
U2 = n1n2 + n2(n2+1)/2 - Sigma R
your formula for U-statistic is different. I could not find that in any statistic book or internet. All of them give the listed above formula.
would appreciate if you could answer that.
Thanks,
Bhaskar
Cause this just would make sense with a sample size bigger than the one in the video.
You use the z statistic if your sample size is at least bigger than 20, in this case in the video, it is not, so he took the u statistic instead.
same question. our professor used that formula so i got confused.
The formula is different, but the values calculated for U1 and U2 are just exchanged. This is because the above formula just subtracts the formula used in the video from n1n2. In the end while selecting the min(U1,U2) it wouldn’t matter if the values of U1 and U2 are exchanged. But still, I wonder why change the formula anyway.
Also because a z statistic assumes a normal distribution but here the data isn't.
You helped me to pass my exam .
Thanks a lot !
This was very useful. Thank you!
Thank You, Sir
Excellent...Well explained👏
According to Wikipedia Ua+Ub should equal Na*Nb. in my data set i have 2 groups for a total of 126 responses. Na=67 Nb=59. Responses range between 0 and 10 in their value.
Group A has:
17 responses of 0 ranked at 11.5
3 responses of 1 ranked at 26
4 responses of 2 ranked at 33
5 respoonses of 3 ranked at 44
6 responses of 4 ranked at 55.5
20 responses of 5 ranked at 78.5
2 responses of 6 ranked at 99
3 responses of 7 ranked at 103
2 responses of 8 ranked at 110
0 responses of 9
and 5 responses of 10 ranked at 120.5
Group B has
5 responses of 0 ranked at 11.5
4 responses of 1 ranked at 26
3 responses of 2 ranked at 33
10 responses of 3 ranked at 44
2 responses of 4 ranked at 55.5
18 responses of 5 ranked at 78.5
1 responses of 6 ranked at 99
2 responses of 7 ranked at 103
7 responses of 8 ranked at 110
0 responses of 9
and 7 responses of 10 ranked at 120.5
So I calculated my Ua and Ub and tried to check whether I did it right, However, when i add Ua and Ub i get 3985, whilst Na*Nb amounts to 3953. So i must be doing something wrong. I have no clue what. Does anyone have any clue what is going wrong?
Happens almost fail-proof. You calculate something wrong, and you know it is but not why... as soon as you start panicking and flailing around until you give up and ask others for help you see your mistake...., Mine was that i calculated the U's wrong. I did Ua= Ra-((Na(Nb+1)/2) instead of Ua=Ra-((Na(Na+1)/2)..... Aaaanyway thanks a bunch for the vid, also helped me alot. Cheers from the Netherlands!
you’re amazing ! thank you so so much
Thanks, Eugene!
Very clear and strait to the point thanks
Thank you. I understand this so much better now
Thanks so much, you just saved my psychology group´s life!
I got an A 🥳🥳 thank you!!
Very concisely and clearly explained, thank you
Very informative! Thank you!
How delightfully easy to understand! :)
One correction whenever your stat value is less than critical value then we accept null hypothesis and reject alternative hypothesis
Thank you very much. It helped me a lot.
Thanks.very easy to understand the way you taught us
The explanation was very clear, thank you for sharing it.
I would like to make a suggestion - include a slightly more elaborate example that connects these numbers to the real world. In this case you mentioned that the numbers came from the results of two distinct treatments. For me it would be more helpful if that was accompanied by something like "The numbers you see correspond to the number of lesions that remained on a person's body after treatment was applied; thus we want to compare the lesion-healing effects of drug A and drug B".
This would make the problem less abstract. Otherwise there is a chance that some people will be able to do the number-crunching, but struggle to come up with an answer when asked "so where can you apply this?".
Thank you so much! Made it super easy for me.
You, Sir, are too the point !! Kudos!
super comprehensive. thanks
thank you great lecture!
So grateful! Thank you!!
I love it so much. Thanks so much
Thankyou random Irish man you saved my geography work horrayyy🎉🎉
Very nicely explained
Thank you! You made me actually understand the test. Wow.
Thank you for your kind explanation. It really helpful. Thank you very much.
Fantastic video. Thank you Eugene
This was so helpful. Thank you!!
Thank you for this sir!
Mr. Eugene if you are a class teacher and you conduct exams for two different classes but in the subject. mathematics two data is different in number one class is 32 and one class is 14. they are both skewed. con you please use this approach to compare the performances between theses classes?
Hi! If there are more than two similar ratings in my data, how to rank them? Thank you
Very Useful.. Thank you sir!
why we have rejected the null hypothesis even we know that Ustat< Ucritical
You are an absolute godsend xx
Thanks a lot,well explained❤
Great video, really well explained. Thank you!
Thank you good sir!
Useful to precision