Drexel dragonThe Math ForumDonate to the Math Forum

Search All of the Math Forum:

Views expressed in these public forums are not endorsed by Drexel University or The Math Forum.

Math Forum » Discussions » sci.math.* » sci.stat.math.independent

Topic: Cohen d
Replies: 1   Last Post: Nov 8, 2012 12:05 PM

Advanced Search

Back to Topic List Back to Topic List Jump to Tree View Jump to Tree View   Messages: [ Previous | Next ]
Luis A. Afonso

Posts: 4,743
From: LIsbon (Portugal)
Registered: 2/16/05
Cohen d
Posted: Nov 1, 2012 4:50 PM
  Click to see the message monospaced in plain text Plain Text   Click to reply to this topic Reply

Hodges g, Cohen d, GOOD FOR WHAT?

Karl L. Wuensch (2008)
__This document is a guide for my students in Experimental Psychology . . .

An example on significance difference between two groups:
__Group 1 : N=6, Mean=22.67, St.dev.=4.274
__Group 2 :___8,______ 13.25,_______4.083

_______g = (22.67-13.25)/4.15 = 9.42/4.15 = 2.27
very large effect following Hedges.
Applying the standard NHST, with the current d, Student t, 6 + 8 - 2 = 12 degrees of freedom, one tail, 5% significance level, critical value= 1.782
_______T = (9.42 - d)/ 4.15 = 1.782
_______d = 9.42 - (1.782*4.15) = 2.02
And the difference on Population mean values is at least 2.02 with 95% confidence. Simply as this . . . better than Cohen-Hodges procedure because provides a numeric alpha and uses the conventional NNHST (my acronym for no-null hypotheses statistical test . . .)

Luis A. Afonso[b][/b][i][/i][u][/u]

Message was edited by: Luis A. Afonso

Date Subject Author
Read Cohen d
Luis A. Afonso
Read Re: Cohen d
Luis A. Afonso

Point your RSS reader here for a feed of the latest messages in this topic.

[Privacy Policy] [Terms of Use]

© Drexel University 1994-2015. All Rights Reserved.
The Math Forum is a research and educational enterprise of the Drexel University School of Education.