# Professor Andy Field

• Is it possible to use SPSS to estimate standard deviations alongside projected means in a mixed model analysis? Thanks!

• I was wondering if anyone on the discovering statistics forum could help with my question of how to formally report parameter estimates of a covariate of an ANCOVA?
The  research questions of my dataset are whether there is an initial visual processing deficit in
developmental coordination disorder? And if so does a visuo-motor training programme improve[Read more]

• Stories of African American Graduates of Online Doctoral Programs Needed!

Cathy Evans, a doctoral student at Walden University, is conducting a study.  African American doctorate recipients who attained a doctorate from online doctoral psychology programs at Title IV privately operated for-profit, online institutions that practice open admission ([Read more]

• Hi all,
I’m very pleased to let you know that SAGE has recently set up a new Facebook page about all things Andy and Discovering Statistics, where we’ll be posting news, free stuff, photos, videos, competitions and more. We’ve just posted the second video in our Ask Andy Anything series which is well worth a watch! Hope you can join us over[Read more]

• I’m sorry that I posted a new discussion item as a comment to this thread. I now understand where it should have gone.

• Hi,
I am new to R and am learning using DSUR. On page 78 it is suggested that we load a package called DSUR in order to have handy the functions in the book. The current DSUR package is not compatible with R v 2.15.2. Do we simply cut and paste from the book’s website? Is there a new DSUR package out there that I have missed?

All the best,

C Moller

• Thanks Katie. Have sent to the group hoepefully with luck i will get some hints.

• Hi everyone,
I am doing ROC Curve analysis to establish cut-off points for a scale. I calculated Youden’s index to establish cut-off points, however to my despair, the Youden’s index is equal for two of the scores:
Let’s say my subjects could score between 10-20 on a scale and the Youden’s index is the highest at 124.5 for scores 15 and 16 on this sc[Read more]

• Dear Andy and All
I have a question about data transformations. Consider the following explanation written by Andy:
“As such, transforming the data won’t change the relationships between variables (the relative differences between people for a given variable stay the same), however, it does change the differences between different variables (because it[Read more]

• Mutasem,
There’s a decent description of post hoc tests here: http://pages.uoregon.edu/stevensj/posthoc.pdf

In short, different post hoc tests scale the F-ratio differently. Depending on how the F-ratio is distributed, you may end up with n.s. contrasts (common in Scheffe’s method).

• Hello
I wonder how is it possible to get a significant omnibus F in one-way ANOVA, and getting no significant differences in a post hoc test ?

• omeone posed me this question:

Some of my research, if not all of it (:-S) will use multiple correlations. I’m now only considering those correlations that are less than .001. However, having looked at bonferroni

• This blog was published recently showing that the use of R continues to grow in academia. One of the graphs (Figure 1) showed citations (using google scholar) of different statistical packages in academic papers […]

• ’ve been thinking about writing a blog on one-tailed tests for a while. The reason is that one of the changes I’m making in my re-write of DSUS4 is to alter the way I talk about one-tailed tests. You might wonder why I w

• Like buses, you don’t get a blog for weeks and then two come at once. I saw today this headline: Does listening to rock make you racist? Seven minutes of Bruce Springsteen makes students favour white people over others in t

• ****Warning, some bad language used: don’t read if you’re offended by that sort of thing****

I haven’t done a blog in a while, so I figured I ought to. Having joined Twitter a while back, I now find myself suffering f

• My friend Jeremy Miles sent me this article by Basto and Periera (2012) this morning with the subject line ‘this is kind of cool’. Last time I saw Jeremy, my wife and I gatecrashed his house in LA for 10 days to discuss wri

• yey I am part of this group…

• Having spent several weeks reading the proofs of my R textbook (that was dull I can assure you), I’m finally about to start thinking about the SPSS book update (a month late). I already have ideas about what c […]

• There have been a few news stories recently about misunderstanding of statistics; especially confusing correlation with cause. For example, the Guardian ran this story/tutorial (http://t.co/AwCugVIV). Hot on the heels of