Finding mixed cases in exploratory factor analysis
Abstract Two methods are presented that allow for identification of mixed cases in the extraction of general factors. Simulated data is used to illustrate them. Introduction General factors can be…
Harvard SAT and IQ: How much regression towards the mean?
http://pumpkinperson.com/2015/04/13/is-the-sat-an-iq-test/ Blog commenter Lion of the Judah-sphere has claimed that the SAT does not correlate as well with comprehensive IQ tests as said IQ tests correlate with one another. At…
How exactly does one properly remove the effect of one variable? Residuals, partial correlation, multiple regression, semi-partial?
I ran into trouble trying to remove the effects of one variable on other variables doing the writing my reanalysis of the Noble et al 2015 paper. It was not…
International differences in intelligence can be confusing: A commentary on Harrison et al (2015)
Abstract In this commentary I explain how mean differences between normal distributions give rise to different percentages of the populations being above or below a given threshold, depending on where…
Automatic testing of all possible multiple regression models given a set of predictors
Abstract Researcher choice in reporting of regression models allow for questionable research practices. Here I present a function for R that reports all possible regression models given a set of…
Two very annoying statistical fallacies with p-values
Some time ago, I wrote on Reddit: There are two errors that I see quite frequently: Conclude from the fact that a statistically significant difference was found to that a…
Understanding restriction of range with Shiny!
I made this: https://emilkirkegaard.shinyapps.io/Understanding_restriction_of_range/ Source: # ui.R shinyUI(fluidPage( titlePanel(title, windowTitle = title), sidebarLayout( sidebarPanel( helpText("Get an intuitive understanding of restriction of range using this interactive…
Simpler way to correct for restriction of range?
Restriction of range is when the variance in some variable is reduced compared to the true population variance. This lowers the correlation between this variable and other variables. It is…
Correlations and likert scales: What is the bias?
A person on ResearchGate asked the following question: How can I correlate ordinal variables (attitude Likert scale) with continuous ratio data (years of experience)? Currently, I am working on my…
Workgroup: Doing Bayesian Data Analysis: A Tutorial Introduction with R and BUGS
I started a workgroup for going thru the Doing Bayesian Data Analysis: A Tutorial Introduction with R and BUGS book. See thread on forum.