The Kruskal-Wallis Test

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  • Опубликовано: 2 фев 2025

Комментарии • 100

  • @aureliohess9349
    @aureliohess9349 7 лет назад +11

    Dear teacher, it was a wonderful explanation. Very clear and didactic. Thank you very much.

  • @rukhsanazaidi629
    @rukhsanazaidi629 8 лет назад +7

    You are amazing. Seriously. Such an amazing presentation. So clearly explained. Thanks so much.

  • @joanwaithera7485
    @joanwaithera7485 3 года назад

    I love this channel, thank you❤

  • @SuhasBajgurMD
    @SuhasBajgurMD 13 лет назад +4

    I really like the way you simplify the process into numerous steps. Now, I know what exactly is the logic behind those calculations when I use STATA. Thank you very much :)

  • @anandakrishnan844
    @anandakrishnan844 5 лет назад +1

    I regret not finding this channel before.

  • @anandakrishnan844
    @anandakrishnan844 5 лет назад +2

    This is just so clear and beautifully explained.

  • @kareenkk356
    @kareenkk356 2 года назад

    I watched many videos and read many sites this tutorial only made it clear what is df and h statistic value. Thank you very much.

  • @vinamramishra7157
    @vinamramishra7157 25 дней назад +1

    awesome!

  • @sudhak8073
    @sudhak8073 8 лет назад +2

    Excellent presentation. Thank you....

  • @Scynikk
    @Scynikk 10 лет назад +28

    I sleep during lectures and my professor is brain dead. Thanks a lot for the help.

    • @muhammadumair7781
      @muhammadumair7781 6 лет назад +6

      Respect Teachers Plz.

    • @danieleatzeni3400
      @danieleatzeni3400 4 года назад +3

      @@muhammadumair7781 when they deserve respect, they are respected. Respect is not granted, is obtained through competence.

  • @mikezimmer999
    @mikezimmer999 13 лет назад +1

    Hello. Excellent video! Question for you: In the formula for 'h' there was a numeric value of 3. Is this because there are 3 groups? In other words, if I have two groups (say, males and females) rather than 3, would I use 2 in the formula? Thanks! Mike

    • @woodchuk1
      @woodchuk1 7 лет назад

      Michael Zimmer No, that 3 is a constant, as is the 12 in the numerator of the fraction on the left hand side.

  • @onlyyouareworthy
    @onlyyouareworthy 8 лет назад +1

    Brilliant explanation man. Really well done.

  • @lanzcordero2132
    @lanzcordero2132 4 года назад

    this is actually very clear! Kudos!

  • @yungeodubbleg
    @yungeodubbleg 10 лет назад

    Video of the year

  • @AGaneshKumar73
    @AGaneshKumar73 10 лет назад +1

    Really very useful and thanks a lot..!

  • @fmwan1
    @fmwan1 8 лет назад +1

    Lovely, thank you! 😊

  • @surajisenanayake4345
    @surajisenanayake4345 3 года назад

    Very clear. Thank you.

  • @patte7k
    @patte7k 13 лет назад

    Great work!!!!

  • @wasafisafi612
    @wasafisafi612 3 года назад

    Thank you for the explanation

  • @tinalovesboston
    @tinalovesboston 12 лет назад +1

    Thank you for your fast reply. I realized my error- I was averaging the wrong column for the mean ranking so I had rank values that were lower than what they should have been. I was trying to compare the responses for the three different groups, but I'm thinking the one-way ANOVA is the best test. Thanks!

  • @ginalynmostrales3145
    @ginalynmostrales3145 3 года назад

    Wow, very brief and concise... My thanks

  • @faizaalee353
    @faizaalee353 5 лет назад

    so well explained GOD bless you

  • @rohankoroth2410
    @rohankoroth2410 10 месяцев назад

    Thank you very much for the easy and wonderful explanation

  • @mustafapoison6546
    @mustafapoison6546 2 года назад

    perfectly done

  • @ceriamargareta8117
    @ceriamargareta8117 2 года назад

    Thank you so much❤

  • @marcianasedentario7981
    @marcianasedentario7981 2 года назад

    It' helps a lot to me as a beginner.
    Thank you very much for imparting and sharing your knowledge ♥️

  • @vismayadinesh745
    @vismayadinesh745 7 лет назад +1

    thank you for your lecture......

  • @mroosie7488
    @mroosie7488 4 года назад

    Great video

  • @dylanparker130
    @dylanparker130 6 лет назад +1

    thank you so much - this helped a lot

  • @siddharthmohansingh6065
    @siddharthmohansingh6065 4 года назад

    Thank You Sir !

  • @tinalovesboston
    @tinalovesboston 12 лет назад

    P.S. The reason why I was used this test initially was due to the Likert Scale. I read that using a one-way ANOVA isn't a good idea for scores ranging from 1-5, 1=strongly disagree, 5=strongly agree. Thanks again!

  • @kajagrkova8546
    @kajagrkova8546 2 дня назад

    can this test be done if we only have 3 data sets for each group

  • @ayushbhosle1553
    @ayushbhosle1553 Месяц назад

    amazing explaination

  • @SNIPE263
    @SNIPE263 4 года назад

    nice and clear. Thanks!

  • @Draven.G
    @Draven.G 9 лет назад +1

    Which test can i use in case i need to use a non-parametric two way ANOVA? From what i understand, Kruskal-Wallis test is the non-parametric alternative for one way ANOVA

    • @woodchuk1
      @woodchuk1 8 лет назад

      Assuming that you have two way ANOVA with replication (where each combination of the two factors has more than one data point), and that all combinations have the same number of elements (that is, the ANOVA is balanced) and that this number is at least 5, you can use a test called the Schierer Ray Hare test as a nonparametric alternative to two way ANOVA. Reply back to me if you want the details.

  • @sasohataba1
    @sasohataba1 12 лет назад

    رااااااااااااااااااااااااااااااائع جدا ...............شكرا

  • @parithimathi
    @parithimathi 2 года назад

    நன்றி. எளிதாகப் புரிந்தது.

  • @minshugarg8166
    @minshugarg8166 11 лет назад +1

    Actually I have a question sir. I understood everything in the video but what will we do if we have tied ranks?
    thanks sir

  • @tamerlanyusifov
    @tamerlanyusifov 4 года назад +1

    Thank you for the video, very clear explanation, but there is one thing that I do not really understand. Why are we using Chi-Square distribution in this question?

  • @ekaarzoo
    @ekaarzoo 3 года назад

    At 5:11 how is N=18? Wasn't it 6?

    • @ellizabtty
      @ellizabtty 2 года назад

      That’s a big N, so you’re multiplying the 3 samples that’s 6*6*6=18 since it’s big N which means total of all 3 Ns. Small n is 6

  • @xitsEHIMEx
    @xitsEHIMEx 11 лет назад +3

    What to you do if participants have the same number in each condition? How would you rank it

  • @selaromnatsirt3949
    @selaromnatsirt3949 5 лет назад +1

    great help!

  • @MJ-ye7dd
    @MJ-ye7dd 3 года назад

    Why is the second table different form the first one?

  • @ahmedisse7641
    @ahmedisse7641 4 года назад

    Thank you sir..
    But If have more than one sig. Value, should I do the average?

  • @autriliarinella
    @autriliarinella 8 лет назад +1

    thanks a lot!

  • @jbvcxtr3056
    @jbvcxtr3056 4 года назад +2

    What happens with the ranks if two numbers are the same, for example you have three 9's. How do you rank them?

  • @beckyb8929
    @beckyb8929 2 года назад

    I watched this video without watching anything else, so where does the 12 come from on the last equation (H=etc)? Otherwise is clear. thank you

    • @woodchuk1
      @woodchuk1 2 года назад

      I believe the 12 comes from the formula for calculating the variance of a uniform distribution, of which a series of rankings would be an example.

  • @soninikul
    @soninikul 11 лет назад +1

    thanks a lot

  • @aregahaile707
    @aregahaile707 12 лет назад

    hi dear how are you doing?
    Could Friedman's test be applied to data from a one-way layout in which there are the same ,n, of observations from each of k treatments? Explain.
    Should Friedman's test be applied to such data? Explain.

  • @kinjaws9606
    @kinjaws9606 6 лет назад

    Quick question (URGENT), in the conclusion you say (2, N=18), p>.05: what is the "2" reffering to, and why p>.05?? Thanks

    • @woodchuk1
      @woodchuk1 6 лет назад

      I've deleted my previous replies since I screwed up...I was using the F statistic for the KW test when I shouldn't have. My error, sorry. The KW test uses the chi-square distribution, which has only one degree of freedom, equal to the number of groups minus 1. So since we have three groups here, we use 2 degrees of freedom in the chi-square distribution, not the F distribution. At an alpha of 0.05, our critical value is 5.991, and since our chi-square value of 2.854 falls short of the critical value, our test statistic cuts off an area greater than 5% on the right side of the curve. So our p value is greater than 0.05 and our value is not significant. The 18 here just refers to the total number of observations, but it's strictly not needed, since we don't have two separate degrees of freedom like we do in the F distribution. All we need for chi-square is the number of groups minus 1. Sorry for the mixup!

  • @PhilipADonahue
    @PhilipADonahue 9 лет назад +2

    I have 24 as my N, and (48sq/8+32sq/8+27sq/8) (the last part is -75).
    After doing this equation I come up with -64.8575 as my H answer.
    It does not seem right that it should be negative.
    Any ideas?

    • @woodchuk1
      @woodchuk1 8 лет назад +1

      The sum of your ranks must be wrong...if you have 24 scores, the left side of the KW statistic (12/(24*25)) simplifies to 1/50. You would subtract 75 from the end, as you have done. If each group has 8 values, your denominators are correct. The only other part is the numerators...check your ranks again to make sure the sums are correct. They're too low if you're getting a negative result.

    • @woodchuk1
      @woodchuk1 8 лет назад

      +woodchuk1 The sums of your ranks should be equal to (1+2+3+...+24), or 300. So the numerators for each group should add to give 300.

  • @roseb2105
    @roseb2105 7 лет назад

    what does the h test statistic mean exactly? why do we choose this formula? So let me get this straight my conclusion in this case would tell me me of some difference between my samples and the chi values tell me the probablity of having some number difference between my samples? I understand how to calculate the formula but how is it derived i dont want to just memorize it?

  • @neillpatterson
    @neillpatterson 13 лет назад

    You ranked the data but then never used the results of that. Since you are doing a chi-squared test, are you supposed to subtract the actual data from the ordinal rank and square that quantity?

  • @tinalovesboston
    @tinalovesboston 12 лет назад

    I am analyzing survey scores for three questions using a Likert Scale (1=Strongly disagree to 5=Strongly agree) for three independent groups. Unfortunately, here is the breakdown for the first question:
    Score # Respones
    1 0
    2 0
    3 1
    4 21
    5 64
    As a result, I have only 3 ranks, low in value, yielding a negative H value. Am I doing the right test?

  • @aidan7646
    @aidan7646 3 года назад

    What if when youre ranking you have lots of the same values?

  • @chuyuri3776
    @chuyuri3776 8 лет назад +1

    u helped me a lot!!!1

  • @cionasha-ked6907
    @cionasha-ked6907 4 года назад

    what happens if I have different sample sizes?

  • @MrStefan135
    @MrStefan135 11 лет назад

    How would you put the formula on the calculator? It doesn't match your answer for the test statistic

  • @aravindssingapore4327
    @aravindssingapore4327 4 года назад

    Kruskal Wallis sounds like a Pokémon's name.

  • @shalamandy10
    @shalamandy10 7 лет назад +1

    thanks

  • @Jonpaulim
    @Jonpaulim 3 года назад

    Hi great video I have subscribe can I ask a question please

  • @MIZRAIM1984
    @MIZRAIM1984 5 лет назад

    The tables for H values in respect to K-W test look different.

    • @jm6610
      @jm6610 5 лет назад

      I was thinking the same. The alpha = 0.01 column looks different.

  • @Siwsonvirusman
    @Siwsonvirusman 10 лет назад

    Thanks!

  • @aregahaile707
    @aregahaile707 12 лет назад +1

    Show that maximum value of Friedman test statistic, s, is Smax=n(k-1)

  • @rc823
    @rc823 2 года назад

    Hello guys,
    where can i find the Table with alpha and df online ? Does anyone have a link for me ?:) I need the source from the table for my excercise :) Thanks

  • @kiransuz8226
    @kiransuz8226 4 года назад

    Please do write down your source also

  • @WA-hq6ls
    @WA-hq6ls 4 года назад

    good enough

  • @taylortalarico2729
    @taylortalarico2729 8 лет назад +1

    can anyone explain to me how to solve the equation? how do they get 2.84??

    • @woodchuk1
      @woodchuk1 7 лет назад +1

      39^2/6 = 253.5
      65^2/6 = 704.167
      67^2/6 = 748.167
      253.5 + 704.167 + 748.167 = 1705.834
      1705.834 * 12 = 20470.008
      20470.008/(18*19) = 59.854
      59.854 - (3)(18 + 1) = 2.854

    • @brandonpaquette1762
      @brandonpaquette1762 6 лет назад

      woodchuk1 I love you so much

  • @mycollection5935
    @mycollection5935 9 лет назад +1

    is it possible that the group 1 has 6,6,6,6,6,6,6,8,6,66,8,6 and group 2 8,8,8,8,8,8,6,8,8,8 and group 3 10,10,8,10,10,10,8,10....how can i rank these? oh my g....pls help

    • @woodchuk1
      @woodchuk1 8 лет назад +1

      First, let's assume that the 66 was meant to be two 6's. Then, I get that we have 12 6's, 13 8's, and 6 10's. If the 6's were all distinct, they would occupy ranks 1-12 in numerical order. Since they are identical, we assign each 6 the average rank of 1-12 (1+2+3+...+12, all divided by 12), which is 6.5. Likewise, the 8's would occupy ranks 13-25 if distinct; averaging as before, I get 19 to be used as the rank for all the 8's. Lastly, the 10's would occupy ranks 26-31, so they would all receive an average rank of 28.5. Run the KW test using these ranks, and divide the result by 0.864919 as a correction factor for the extensive ties. That's your answer. If you want more info, message me back.

    • @woodchuk1
      @woodchuk1 8 лет назад +1

      +woodchuk1 The correction factor should be 0.861895 instead...sorry for the error! It makes no difference in this case, as the correction factor always increases the value of the test statistic, which was already far over the critical value before the correction in this case. So your conclusion would have been the same either way.

    • @autriliarinella
      @autriliarinella 8 лет назад +1

      well in my opinion if you have the same score perhaps you can do this:
      You know in the group one 6 is the smallest score (since the biggest is 8), then it should be put before the 8 score. The problem is you have no idea whats the rank for each 6 score since there are eleven of 6 score, then to know the exact rank all you have to do first is divide the first and second rank so you can get the rank for each 6 score.
      Example:
      6,6,8,7----> supposed to have 4 ranks, but oops we have the same score. But 6 is the smallest, so it must be put in the first and second rank before 7 and 8. But whats the exact rank for them?
      (1+2)/2: 1,5.
      So the rank for each of them is 1.5
      Since you have more than two of 6 score then you have to do this several times.

  • @steven_grande
    @steven_grande 11 лет назад

    This is actually exactly what I want to do, how to do it on excel?

  • @sjornlim5301
    @sjornlim5301 10 лет назад +1

    how to find critical level

  • @mansoorehjami7493
    @mansoorehjami7493 8 лет назад

    Perfect explanation.tnx

  • @vkys4594
    @vkys4594 10 лет назад

    please tell me how to code semantic differential scale in SPSS

  • @neillpatterson
    @neillpatterson 13 лет назад

    @statslectures
    OK nevermind, I missed something you said. At 3:10 you say that you replace the data in your original table with the ranks. That's what I was missing, hence my misinformed comment.

  • @montymondal3709
    @montymondal3709 4 года назад

    Excuse me your formula is not visible due to your subtitle.

  • @pranjalnath6850
    @pranjalnath6850 7 лет назад

    Thnx

  • @jamaecajalata7220
    @jamaecajalata7220 6 лет назад

    😍😍😍😍

  • @meeteshdhulapkar
    @meeteshdhulapkar 2 года назад

    Sir thank you:
    Translated by google

  • @patelsourabh7291
    @patelsourabh7291 5 лет назад

    Bro the smallest value is one

  • @rupeshraut727
    @rupeshraut727 4 года назад

    H

  • @rupeshraut727
    @rupeshraut727 4 года назад

    V

  • @rupeshraut727
    @rupeshraut727 4 года назад

    H

  • @rupeshraut727
    @rupeshraut727 4 года назад

    H