iSixSigma

Power

Viewing 25 posts - 1 through 25 (of 25 total)
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  • #49452

    Whitehurst
    Participant

    Hello,
    I know that the “Power” of an experiment is important to make sure the correct answer is obtained, but I am having trouble getting my head round how “Power” works and how to calculate the level of power within an experiment.  Can anyone help – in lay mans (or womans!) terms?
    Thanks
    Joe
     

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    #169034

    Ryan
    Member

    Statistical power is defined as the probability of rejecting a false null hypothesis. It is 1 minus beta, where beta is the probability of failing to reject a false null hypothesis. Power depends upon alpha (Type I Error), beta (Type II Error), sample size, effect size, and the directionality of the statitsical test. Generally speaking, statisticians try to increase power by increasing sample size. You will need to use a statistical software program or tables to compute power.

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    #169304

    Jen
    Participant

    Joe,
    Think of power in this manner.  If there is a distribution of innocent people that get pulled into a court of law charged with a crime they did not commit then the alpha risk is the portion of that distribution of people that have bad lawyers, planted evidence and a corrupt judge.  The power comes from another distribution that consists of really bad people that definitely commit crimes.  The power comes from the risk of the judge/jury thinking that you may belong to this particular group because they have been able to shift their distribution towards the innocent distribution through the use of a great lawyer and getting rid of the evidence.  As the criminal distribution begins to over lap the innocent distribution, the amount of the criminal distribution that is overlapped is the power.  If you can give me your email I will send you a power point that makes this more clear because you can then see the pictures.

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    #169305

    TE
    Member

    Joe:
    Could you send a copy of your ppt at teyang at hotmail.com? Thank you.
    Te
     

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    #169306

    Swaggerty
    Participant

    Same here, Joe…I’ve been trying to explain it to a bunch of guys without getting them muddled up.
    Email id is [email protected]

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    #169307

    Lee
    Participant

    Please send the ppt.  Thanks in advance.
    [email protected]

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    #169312

    Neo
    Participant

    can you please send me a copy too.
    [email protected]
     
    thanks in advance

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    #169316

    Eoin Barry
    Participant

    Hello Jen – I would appreciate a copy of that presentation too :)
    Best regards,
    Eoin
    [email protected]

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    #169324

    Rhonda
    Member

    Hi Jen,
    I would be interested in seeing a copy of the presentation as well. Please send it to [email protected].
    Thank you

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    #169325

    ong
    Member

    Hi Jen,
    Please forward me a copy of the power presentation also.
    Regards
    Rob
    [email protected]
     

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    #169340

    Joe Nolan
    Participant

    Thanks very much for all you help.
    cheers
    Joe

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    #169343

    Craig
    Participant

    A good visualizaton of this concept can be seen if you download a trial copy of JMP, and then download the Oneway ANOVA script. This is a dynamic illustration of relationhip of sample size, alpha, power, difference to detect, etc.

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    #169344

    Sorour
    Participant

    I would greatly appreciate a copy of the PPT.
    My email is (a3echo9 @ yahoo dot com )
    Thanks

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    #169345

    Jen
    Participant

    Paul,
    I tried sending it to the email you gave me and I am getting an undeliverable message.
     
    jen

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    #169346

    Sorour
    Participant

    Lets try my trusted an proven email addy.
    Thanks
    [email protected]

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    #169347

    Jen
    Participant

    Neo,
    I get an undeliverable message when I send to the address you provided me with.  Do you have another?
     
    Jen

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    #169378

    Melody
    Participant

    Hi Jen,
    Could you share your ppt with me as well? Thanks!!
    [email protected]

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    #169380

    aiman farid
    Participant

    Hi everybody,
    I am interested in power, errors & sample size, May I share your PPT?
    Thanks alot in advance. [email protected]
    Aiman

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    #169386

    sree
    Member

    hi
    could u share ppt to my e-mail ID p_s[email protected]
    thanks

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    #169388

    Spielberg
    Member

    Jen
    Please send it to my [email protected]
    and I may share with you an impressive PPT on DFSS,
    thanks and regards

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    #169464

    MC Wall
    Participant

    Jen,
    Could you please  send a copy to me as well? [email protected].
     
    Thanks for sharing!

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    #169498

    Grosvenor
    Participant

    Jen,
    Please forward a copy to me, also.
    Thanks in advance.
    Chuck

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    #169499

    Grosvenor
    Participant

    Jen,
    Pls forward a copy of the ppt you mentioned to:
    [email protected]
    Thank you
    Chuck

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    #169511

    VJ
    Member

    Jen,
    would appreciate a copy of the ppt to this address
    [email protected]
    Many thanks in advance.

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    #169699

    Ashman
    Member

    Joe: would you please send me a copy of your Power Point – sounds like many like it – it must be good!!
    Thanks Steve

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