Finding P value - Explain












0












$begingroup$


def get_pvalue(con_conv, test_conv,con_size,  test_size,):  
lift = - abs(test_conv - con_conv)
scale_one = con_conv * (1 - con_conv) * (1 / con_size)
scale_two = test_conv * (1 - test_conv) * (1 / test_size)
scale_val = (scale_one + scale_two)**0.5
p_value = 2 * stats.norm.cdf(lift, loc = 0, scale = scale_val )
return p_value


I have this function and I would like to know that what it is actually doing and how it is actually calculating the p-value.



This is to find the difference between the conversion rate of control and test and group from an A/B test.



con_conv--> Conversion rate for control group
test_conv--> Conversion rate for test group
con_size --> population size for control group
test_size --> population size for test group


I understand that at scale_one and scale_two they are calculating the variance for each group but I don't understand that why they are adding both of them to calculate the standard deviation and why they are multiplying the cdf with 2 to get the p_value. If anyone can explain that would be awesome!









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$endgroup$

















    0












    $begingroup$


    def get_pvalue(con_conv, test_conv,con_size,  test_size,):  
    lift = - abs(test_conv - con_conv)
    scale_one = con_conv * (1 - con_conv) * (1 / con_size)
    scale_two = test_conv * (1 - test_conv) * (1 / test_size)
    scale_val = (scale_one + scale_two)**0.5
    p_value = 2 * stats.norm.cdf(lift, loc = 0, scale = scale_val )
    return p_value


    I have this function and I would like to know that what it is actually doing and how it is actually calculating the p-value.



    This is to find the difference between the conversion rate of control and test and group from an A/B test.



    con_conv--> Conversion rate for control group
    test_conv--> Conversion rate for test group
    con_size --> population size for control group
    test_size --> population size for test group


    I understand that at scale_one and scale_two they are calculating the variance for each group but I don't understand that why they are adding both of them to calculate the standard deviation and why they are multiplying the cdf with 2 to get the p_value. If anyone can explain that would be awesome!









    share







    New contributor




    Kartikeya Sharma is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
    Check out our Code of Conduct.







    $endgroup$















      0












      0








      0





      $begingroup$


      def get_pvalue(con_conv, test_conv,con_size,  test_size,):  
      lift = - abs(test_conv - con_conv)
      scale_one = con_conv * (1 - con_conv) * (1 / con_size)
      scale_two = test_conv * (1 - test_conv) * (1 / test_size)
      scale_val = (scale_one + scale_two)**0.5
      p_value = 2 * stats.norm.cdf(lift, loc = 0, scale = scale_val )
      return p_value


      I have this function and I would like to know that what it is actually doing and how it is actually calculating the p-value.



      This is to find the difference between the conversion rate of control and test and group from an A/B test.



      con_conv--> Conversion rate for control group
      test_conv--> Conversion rate for test group
      con_size --> population size for control group
      test_size --> population size for test group


      I understand that at scale_one and scale_two they are calculating the variance for each group but I don't understand that why they are adding both of them to calculate the standard deviation and why they are multiplying the cdf with 2 to get the p_value. If anyone can explain that would be awesome!









      share







      New contributor




      Kartikeya Sharma is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
      Check out our Code of Conduct.







      $endgroup$




      def get_pvalue(con_conv, test_conv,con_size,  test_size,):  
      lift = - abs(test_conv - con_conv)
      scale_one = con_conv * (1 - con_conv) * (1 / con_size)
      scale_two = test_conv * (1 - test_conv) * (1 / test_size)
      scale_val = (scale_one + scale_two)**0.5
      p_value = 2 * stats.norm.cdf(lift, loc = 0, scale = scale_val )
      return p_value


      I have this function and I would like to know that what it is actually doing and how it is actually calculating the p-value.



      This is to find the difference between the conversion rate of control and test and group from an A/B test.



      con_conv--> Conversion rate for control group
      test_conv--> Conversion rate for test group
      con_size --> population size for control group
      test_size --> population size for test group


      I understand that at scale_one and scale_two they are calculating the variance for each group but I don't understand that why they are adding both of them to calculate the standard deviation and why they are multiplying the cdf with 2 to get the p_value. If anyone can explain that would be awesome!







      python statistics





      share







      New contributor




      Kartikeya Sharma is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
      Check out our Code of Conduct.










      share







      New contributor




      Kartikeya Sharma is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
      Check out our Code of Conduct.








      share



      share






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      Kartikeya Sharma is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
      Check out our Code of Conduct.









      asked 1 min ago









      Kartikeya SharmaKartikeya Sharma

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      New contributor




      Kartikeya Sharma is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
      Check out our Code of Conduct.





      New contributor





      Kartikeya Sharma is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
      Check out our Code of Conduct.






      Kartikeya Sharma is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
      Check out our Code of Conduct.






















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