# Power

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

[email protected]

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#169312

Neo
Participant

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

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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.
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]

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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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Viewing 25 posts - 1 through 25 (of 25 total)

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