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Working with shapefiles, projections and world maps in ggplot
In this post I will show some different examples of how to work with map projections and how to plot the maps using ggplot. Many maps that are shown using their default projection are in the...
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Creating a typical textbook illustration of statistical power using either...
A common way of illustrating the idea behind statistical power in null hypothesis significance testing, is by plotting the sampling distributions of the null hypothesis ($ H_0 $) and the alternative...
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Are the Current Criteria for Empirically Supported Treatments Too Lenient?
The practice of classifying treatments as empirically supported (ESTs) has been widely debated for a long time. Recently Jessica Nasser published an article in the Journal of Contemporary Psychotherapy...
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A while ago I was playing around with the JavaScript package D3.js, and I began with this visualization—that I never really finished—of how a one-way ANOVA is calculated. I wanted to make the...
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Calculating the Overlap of Two Normal Distributions Using Monte Carlo...
I read this post over at the blog Cartesian Faith about Probability and Monte Carlo methods. The post describe how to numerically intregate using Monte Carlo methods. I thought the results looked cool...
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New d3.js visualization: Interpreting Cohen’s d effect size
I have created a new visualization in D3. The purpose is to aid in the interpretation of Cohen’s d. The visualization presents Cohen’s d in the following ways: Visually, Cohen’s U3, Probability of...
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Expected overestimation of Cohen’s d under publication bias
Earlier this week I read this article about “Why Publishing Everything Is More Effective than Selective Publishing of Statistically Significant Results” by Mercal et al (2014). The authors simulated...
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New d3.js visualization: Understanding Significance Testing and Statistical...
Here is a new visualization created in the same manner as my Cohen’s d vizualisation. This new visualization is an interactive display of classical null hypothesis significance testing and statistical...
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Some exploratory evidence that wait-list conditions may act as a nocebo in...
The double-blinded placebo-controlled randomized trial have long been held as the gold standard in pharmacological research. Unfortunately, this design is impossible to mimic in clinical psychology....
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New d3.js visualization: Interpreting Correlations
Here is a new visualization done in d3js. In this visualization I show a scatter plot of two variables with a given correlation. The variables are samples from the standard normal distribution, which...
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Interpreting Confidence Intervals – new d3.js visualization
I just published a new interactive visualization in my series of basic statistical concepts and techniques. This time I have tried to explain confidence intervals for means. This visualization shows a...
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Visualization the distribution of p-values using d3.js
I just published a new interactive visualization in my series of basic statistical concepts and techniques. This time I am trying to show how p-values are distributed. Check it out here:...
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Using R and lme/lmer to fit different two- and three-level longitudinal models
I often get asked how to fit different multilevel models (or individual growth models, hierarchical linear models or linear mixed-models, etc.) in R. In this guide I have compiled some of the more...
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New d3.js visualization: the t-distribution and its normal approximation
I just published a new interactive visualization in my series of basic statistical concepts and techniques. This time I am trying to show how the t-distribution and the normal distribution differs, and...
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Monty Hall Simulations
The Monty Hall ProblemThere've been many simulations of the Monty Hall-problem done in R. But since I'm trying to learn R, I wanted to try to simulate the paradox over many different trails and plot...
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Using Ggplot2 to plot last.fm top 100 albums
I found out that last.fm had made data files available for their Best of 2011 artist list, and I thought it’d be a great opportunity to learn some more about data management in R and Ggplot2. I began...
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Ggplot2, PubMed citation frequency and DSM-IV Axis I disorders by year
IntroductionI an earlier post I used ggplot2 to plot publication count by year for different psychotherapy orientations. I'm using an updated version of that R-code in this post to plot publication...
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Simple data mining and plotting data on a map with ggplot2
IntroductionA Facebook group for psychologists in Sweden created a document where each member could type in were they live and what they work with. At the moment 192 psychologists have added their...
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Does mindfulness aid insight problem solving? New study suggest so
A new study (Ostafin, B. D., & Kassman, K. T, In Press) examined whether mindfulness meditation could help improve participants' insight problem solving skills. Their hypothesis was that...
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How to work with Google n-gram data sets in R using MySQL
IntroductionGoogle Ngram is a corpus of n-grams compiled from data from Google Books. Here I’m going to show how to analyze individual word counts from Google 1-grams in R using MySQL. I’ve also...
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