Quiz Question 1 at the end of lesson 4.1 of the LSSGB ebook

Discussion in 'Six Sigma' started by _19325, May 12, 2019.

  1. _19325

    _19325 Well-Known Member

    Joined:
    Jan 1, 2018
    Messages:
    72
    Likes Received:
    1
    Question regarding Quiz Question 1 for Section 5 Analyze Phase, Lesson 2.15 (can be found at the end of lesson 4.1 of the LSSGB ebook):

    Question: A team wants to test if a new drug reduced pain in the patients. What would be the Type II error?

    a) The new drug really works and team concludes it works

    b) The new drug does not work and team concludes it works
    c) The new drug really works and team concludes it does not work
    d) The new drug does not work and the team concludes it does not work


    The correct answer given is C and the explanation is:

    Type II error fails to reject the null hypothesis when it is false, therefore, if the null hypothesis is the drug, it does not cause a difference in pain levels.

    So the first part of the explanation is the correct definition of type II errors (“Type II error fails to reject the null hypothesis when it is false”), however the second part of the explanation doesn’t make sense and contradicts the first part of the explanation.

    The second part of the explanation states that “if the null hypothesis is the drug, it does not cause a difference in pain levels”. Doesn’t this statement define a type I error and not a type II error? A type I error is rejecting a null when it is true and in this case letter C and the second part of the explanation both reject the drug when it is true. Shouldn’t the correct answer be letter B since your team accepts the null (fails to reject null) when the drug should be rejected?

    For reference here is the correct definition of each error compared to the provided answers (letter B and C):

    Null hypothesis is the drug

    Type I error (alpha risk): Rejecting null when null is true.
    Answer C: The new drug really works and team concludes it does not work

    Type II error (beta risk): Accepting null when null is false.
    Answer B: The new drug does not work and team concludes it works

    Can someone please clarify this for me.
     
    #1
    Last edited: May 12, 2019
  2. Vishesh_8

    Vishesh_8 Well-Known Member

    Joined:
    Jun 12, 2018
    Messages:
    104
    Likes Received:
    16
    The link has been shared with our trainer Urmimala. I will update once it is done :)
     
    #2
  3. _19325

    _19325 Well-Known Member

    Joined:
    Jan 1, 2018
    Messages:
    72
    Likes Received:
    1
    Any update on this?
     
    #3

Share This Page