tutorial

If you fit a model with multiply imputed data, you can still plot the line.

What? If you’re in the know, you know there are three major ways to handle missing data: full-information maximum likelihood, multiple imputation, and one-step full-luxury1 Bayesian imputation. If you’re a frequentist, you only have the first two options.

Sexy up your logistic regression model with logit dotplots

What When you fit a logistic regression model, there are a lot of ways to display the results. One of the least inspiring ways is to report a summary of the coefficients in prose or within a table.

One-step Bayesian imputation when you have dropout in your RCT

Preamble Suppose you’ve got data from a randomized controlled trial (RCT) where participants received either treatment or control. Further suppose you only collected data at two time points, pre- and post-treatment.

Got overdispersion? Try observation-level random effects with the Poisson-lognormal mixture

What? One of Tristan Mahr’s recent Twitter threads almost broke my brain. wait when people talk about treating overdispersion by using random effects, they sometimes put a random intercept on each row?

Example power analysis report

Context In one of my recent Twitter posts, I got pissy and complained about a vague power-analysis statement I saw while reviewing a manuscript submitted to a scientific journal.

Make ICC plots for your brms IRT models

Context Someone recently posted a thread on the Stan forums asking how one might make item-characteristic curve (ICC) and item-information curve (IIC) plots for an item-response theory (IRT) model fit with brms.

Don't forget your inits

tl;dr When your MCMC chains look a mess, you might have to manually set your initial values. If you’re a fancy pants, you can use a custom function.

Yes, you can fit an exploratory factor analysis with lavaan

Purpose Just this past week, I learned that, Yes, you can fit an exploratory factor analysis (EFA) with lavaan (Rosseel, 2012; Rosseel & Jorgensen, 2019). At the moment, this functionality is only unofficially supported, which is likely why many don’t know about it, yet.

blogdown updates prompted a website overhaul: These are my notes

Purpose A few weeks ago, I was preparing to release the second blog post in a two-part series (you can find that post here). During the editing process, I had rendered the files into HTML and tried posting the draft to my website.

Effect sizes for experimental trials analyzed with multilevel growth models: Two of two

Orientation This post is the second and final installment of a two-part series. In the first post, we explored how one might compute an effect size for two-group experimental data with only \(2\) time points.