
1. Re: chisquare test for goodness of fit
khalid norat Jul 27, 2016 9:02 AM (in response to Zainab AlFarsi)Right click on your value field and create Bin

2. Re: chisquare test for goodness of fit
Zainab AlFarsi Jul 27, 2016 9:18 AM (in response to khalid norat)I have created the bin but how to use it in the chisquare test ??

3. Re: chisquare test for goodness of fit
khalid norat Jul 27, 2016 9:25 AM (in response to Zainab AlFarsi)Sorry I think I misunderstood your question.
Your method requires categories but you have bins.
So you need to create categories?
If so to do this create a calculated field,
if [value] >x and [value]< y then A
else if [value] >Y and [value]<z then B
else if...
.....
end
you should be able to use this as a category
I'm sorry that's as much as I can help on this as I have not come across chi calculations but will have a read tonight and get back to you if I learn anything new.
Khalid

4. Re: chisquare test for goodness of fit
Zainab AlFarsi Jul 27, 2016 9:53 AM (in response to khalid norat)yes, but i don't know even how to best catogerize the bins, i.e what bin size is best for my data

5. Re: chisquare test for goodness of fit
khalid norat Jul 28, 2016 1:00 AM (in response to Zainab AlFarsi)Could you share a sample set of the data and the link you are following for the Chi Test again and I can have a look at replicating this for you

6. Re: chisquare test for goodness of fit
Zainab AlFarsi Jul 28, 2016 4:43 AM (in response to Zainab AlFarsi)Attached is the sample data , i have the score data and two catogeries A and B, i want to compare the distribution of the two catogeries.
The example also attached

chiSquaredMultiPopTest.twbx 1.1 MB

Test.csv.zip 2.6 KB


7. Re: chisquare test for goodness of fit
Zainab AlFarsi Aug 1, 2016 4:12 AM (in response to khalid norat)Dear Mr. Khalid , did you have a chance to look at the sample data and the example

8. Re: chisquare test for goodness of fit
khalid norat Aug 2, 2016 2:03 AM (in response to Zainab AlFarsi)Hi Zainab,
Sorry for the delay, I've been a little unwell so only back in the office today.
I'm going to have a look at this now.
Have you got any links explaining the chi squared not to do with tableau.
If you do would definitely help me understand what the tableau report should be doing.
Kind Regards,
Khalid

9. Re: chisquare test for goodness of fit
khalid norat Aug 2, 2016 3:39 AM (in response to khalid norat)Hi Zainab,
After looking at this I need further understanding of what your data is and what you are trying to achieve with Chi Squared.
From my understanding Chi Squared is used to compute the variance of a population.
What are you considering of your population.
We should be using counts of the population how does the score fit into this.
Is the score value a count.
Unfortunately counting the score value does not work.
Applying the chi squared logic isn't too difficult. I just need you to explain more about your dataset.
Kind Regards,
Khalid

10. Re: chisquare test for goodness of fit
Zainab AlFarsi Aug 2, 2016 3:53 AM (in response to khalid norat)Thank you Mr. Khalid
the dataset is a score for two experiment , experiment A and experiment B, I want to compare the score set or distribution in experiment A to experiment B. what I was thinking is to create bins for the score (like 5 bins) and then compare the distribution in A and B according to the bins. This what I was thinking but not sure if it is right or wrong. But definitely I want to compare distribution in experiment A to distribution in experiment B
regard,
and thank you
Zainab

11. Re: chisquare test for goodness of fit
khalid norat Aug 2, 2016 4:22 AM (in response to Zainab AlFarsi)Hi Zainab,
Comparing the distribution of 2 experiments make sense but I'm not sure how the chi squared calculation will satisfy your requirement.

12. Re: chisquare test for goodness of fit
Zainab AlFarsi Aug 2, 2016 5:00 AM (in response to khalid norat)Hi Mr. Khalid
the requirement is to compare the distribution of the two experiments, i searched the net how to compare distributions and i got the Chisquare test, Chisquare has two kind of tests, one of them is test for goodness of fit, which we can compare a sample of data to the whole population as i undestood, so i guss it might work to comapre two distributions

13. Re: chisquare test for goodness of fit
khalid norat Aug 2, 2016 5:21 AM (in response to Zainab AlFarsi)Hi Zainab,
Unfortunately, Statistics is not my forte, If you can explain to me how the sets need to be compared within tableau I can assit in creating the tableau report.
I think what would help is if you apply the chi squared method (if this is indeed what you require) in an excel sheet so you know the desired outputs. Once you have this I can assist in creating this in tableau.
Unfortunately if you still have issues understanding how the chi squared calculation gets applied to your data I am unable to help with this.
What you require is a skilled statistician who can help you with this. Hopefully someone in the forum might have the required skills to be able to do this.
kind Regards,
Khalid

14. Re: chisquare test for goodness of fit
Zainab AlFarsi Aug 2, 2016 5:39 AM (in response to khalid norat)I will try to get some help with the test and might get back if i found something
Thank you