type I, II and power

Discussion in 'CT3' started by deepakraomore, Nov 20, 2014.

  1. C2H6O

    C2H6O Member

    Same table with just columns switched.

    TP FP
    FN TN

    with both P's in the same row and same for N's

    and your table on wikipedia page is

    FP TN
    TP FN

    See this video
    https://www.youtube.com/watch?v=Dsa9ly4OSBk&list=LLJnPqxdVeMk0dJ2h4MgGKuA&index=1
     
  2. Hemant Rupani

    Hemant Rupani Senior Member

    I edited aforesaid quote,I mistakenly wrote False +ve 2 times........
    sorry for inconvenience.

    now this gives,

    \[ \matrix{ & H1:did not lie & H0:Lied \\+ve result & FN(type II error) & TP \\ -ve result &TN & FP(type I error)} \]



    PS: I didn't make table on Wikipedia page ;)
     
    Last edited: Feb 17, 2015
  3. C2H6O

    C2H6O Member

    I don't think you understand what TP, FP, FN, TN means. You can't have FN in the +ve row and FP in the -ve row. +ve row will have two positives (because it's the row of positve result). One of them would be FALSE and other will be TRUE. Similarly for -ve (Regardless of what Ho and H1 are)
     
  4. Hemant Rupani

    Hemant Rupani Senior Member

  5. Hemant Rupani

    Hemant Rupani Senior Member

    \[ \matrix{ & H1:did not lie & H0:Lied \\+ve result & FN(type II error) & TP \\ -ve result &TN & FP(type I error)} \]



    Okay! if I accept it
    \[ \matrix{ & H1:did not lie & H0:Lied \\+ve result & FP & TP \\ -ve result &TN & FN} \]
    then FN gives type I error & FP gives type II error, which is not the definition says.
     
  6. C2H6O

    C2H6O Member

    Because you're using different definition for +ve and -ve result. On this page
    http://en.m.wikipedia.org/wiki/False_positives_and_false_negatives

    "In statistical hypothesis testing the analogous concepts are known as type I and type II errors, where a positive result corresponds to rejecting the null hypothesis, and a negative result corresponds to not rejecting the null hypothesis"

    and you're doing the opposite.

    If you stick with the definitions given on that page, only then FP will be a Type I error and FN a Type II error.
     
  7. Hemant Rupani

    Hemant Rupani Senior Member

    I guess I am not so mature to get it all & being unconfused.
    Thanks! Chill!;)
     
  8. Hemant Rupani

    Hemant Rupani Senior Member

    Hi C2H6O,
    it takes long time........
    but after understanding "Multiple comparisons problem"
    I realize you were correct:D :D
     

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