I am pleased to announce Release 3.6 of the Real Statistics Resource Pack. The new release is now available for free download (Download Resource Pack) for Excel 2007, 2010 and 2013 environments.
The Real Statistics Examples Workbook has been updated to reflect the new release. You can also download this file for free (Download Examples). The website is in the process of being updated to reflect the new features. These changes will be made in the next day or two.
The release only has a few new features, but ones that I hope will be useful to you.
Cronbach’s Alpha
The following new functions have been added:
CALPHA_POWER(ca0, ca1, n, k, tails, α) = the statistical power of Cronbach’s alpha test when ca0 = Cronbach’s alpha in the null hypothesis (H0), ca1 = expected value of Cronbach’s alpha (H1), n = the sample size, k = # of items, tails = # of tails: 1 or 2 (default) and α = alpha (default .05).
CALPHA_SIZE(ca0, ca1, k, pow, tails, α) = the minimum sample size required to achieve power of pow for a Cronbach’s alpha test when ca0 = Cronbach’s alpha in the null hypothesis (H0), ca1 = expected value of Cronbach’s alpha (H1), k = # of items, tails = # of tails: 1 or 2 (default) and α = alpha (default .05).
The Statistical Power and Sample Size data analysis tool has also been updated to support statistical power and sample size calculations for Cronbach’s Alpha.
The Cronbach’s Alpha webpage is being updated to explain how to perform hypothesis testing on Cronbach’s Alpha, including p-value, confidence intervals, power and sample size requirements.
Regression
The Regression data analysis tool has been modified to support analyses with more than 65,500 subjects (the previous limit).
The RegCoeff function now returns two columns: the first with the coefficients and the second with the standard errors of these coefficients.
Bug Fix
The output from the Intraclass Coefficient option of the Reliability data analysis incorrectly displayed the title “Interclass Coefficient”. This has now been corrected (thanks Valerie).
Charles