Publications by Thom
CI for difference between independent R square coefficients
In an earlier blog post I provided R code for a CI of a difference in R square for dependent and non-dependent correlations. This was based on a paper by Zou (2007). That paper also provides a method for calculating the CI of a difference in independent R square coefficients based on the limits of the CI for a single R square coefficient. I’ve...
1128 sym 2 img
VIF and multicollinearity diagnostics
In the book I use the car package to get VIF and other multicollinearity diagnostics. I’ve occasionally found this breaks down (usually through mixing different versions of R on different machines at work home or on the move). I recently saw the mctest package and thought it would be useful to use that as a backup – and also because it offers...
1040 sym 2 img
Chi-Square and the Egon Pearson correction
Looking back at the coverage of the Chi-Square test of independence in the book there are a couple of things I wish I’d gone into greater depth on. First, resolving the debate on the appropriate way to handle small expected values in the test of independence. Second, expanding on residual analysis. First, the issue of small expected values. Gen...
3524 sym
CIs for Spearman’s rho and Kendall’s tau
There are various methods for obtaining CIs for Kendall’s tau and Spearman’s rho. As the underlying data are unlikely to be bivariate normal (or else Pearson’s r would be used) bootstrapping is often recommended – but it doesn’t always perform that well (Bishara & Hittner, 2017). One could also use a Fisher z transformation. This makes ...
2541 sym
Serious Stats: Obtaining CIs for Spearman’s rho or Kendall’s tau
I wrote a short blog (with R Code) on how to calculate corrected CIs for rho and tau using the Fisher z transformation.Serious Stats blog post on CIs for rho and tau Related To leave a comment for the author, please follow the link and comment on their blog: Psychological Statistics. R-bloggers.com offers daily e-mail updates about R news and...
572 sym
Serious Stats: Obtaining CIs for Spearman’s rho or Kendall’s tau
I wrote a short blog (with R Code) on how to calculate corrected CIs for rho and tau using the Fisher z transformation.Serious Stats blog post on CIs for rho and tau Related To leave a comment for the author, please follow the link and comment on their blog: Psychological Statistics. R-bloggers.com offers daily e-mail updates about R news and...
572 sym
A quick overview of the egocentric relation event model (EREM) with linked examples in R: part 1
This post is based on an interdisciplinary collaboration (between anthropologists and psychologists) with Kate Ellis-Davies and Sheina Lew-Levy (who initiated the project), Eleanor Fleming and Adam Boyette. The work was recently published in Field Methods and is available here: Demonstrating the Utility of Egocentric Relational Event Modeling Us...
5245 sym