Tag: d3

Visualizing and interpreting Cohen’s d effect sizes

Visualizing and interpreting Cohen’s d effect sizes

Cohen’s d (wiki) is a statistic used to indicate the standardised difference between two means. Resarchers often use it to compare the averages between groups, for instance to determine that there are higher outcomes values in a experimental group than in a control group.

Researchers often use general guidelines to determine the size of an effect. Looking at Cohen’s d, psychologists often consider effects to be small when Cohen’s d is between 0.2 or 0.3, medium effects (whatever that may mean) are assumed for values around 0.5, and values of Cohen’s d larger than 0.8 would depict large effects (e.g., University of Bath).

The two groups’ distributions belonging to small, medium, and large effects visualized

Kristoffer Magnusson hosts this Cohen’s d effect size comparison tool on his website the R Psychologist, but recently updated the visualization and its interactivity. And the tool looks better than ever:

Moreover, Kristoffer adds some nice explanatons of the numbers and their interpretation in real life situations:

If you find the tool useful, please consider buying Kristoffer a coffee or buying one of his beautiful posters, like the one above, or below:

Frequentisme betekenis testen poster horizontaal image 0

By the way, Kristoffer hosts many other interesting visualization tools (most made with JavaScript’s D3 library) on statistics and statistical phenomena on his website, have a look!

Visualize graph, diagrams, and proces flows with graphviz.it

Visualize graph, diagrams, and proces flows with graphviz.it

Graphviz.it is a free online tool to create publication-ready diagrams in an interactive fashion. It uses

It uses graphviz-d3-renderer Bower module and adds editor and live preview of code. Try it on Graphviz fiddling website.

Here are some examples:

A diagram of state transitions
A very complex… graph?
Some clusters with subgraphs

The github page hosts more details and you can even follow the development on twitter.

Record2, apparently
Job-Switching Behaviors in the USA

Job-Switching Behaviors in the USA

Nathan Yau – the guy behind the wonderful visualizations of FlowingData.com – has been looking into job market data more and more lately. For his latest project, he took data of the Current Population Survey (2011-2016) a survey run by the US Census Bureau and Bureau of Labor Statistics. This survey covers many topics, but Nathan specifically looked into people’s current occupation and what they were doing the year before.

For his first visualization, Nathan examined the percentage of people switching jobs (a statistic he dubs the switching rate). Only occupations with over 100 survey responses are shown:

Nathan concludes that jobs that come with higher salaries and require more training, education, and experience have lower switching rates. The interactive visualization can be found on FlowingData.com

Next Nathan looked into job moves within job categories, as he hypothesizes that people who decide to switch jobs look for something similar.

Nathan concludes that job categories with lower entry boundaries are subjected to more leavers. Original on FlowingData.com

The above results in the main question of the blog: Given you have a certain job, what are the possible jobs to switch to? The following interactive bar charts gives the top 20 jobs people with a specific job switched to. In the original blog you can specify a job to examine or ask for a random suggestion. I searched for “analyst” in the picture below, and apparently HR professional would be a good next challenge.

The interactive visualization can be found on FlowingData.com

Nathan got the data here, prepared it in R, and used d3.js for the visualizations. I’d have loved to see this data in a network-kind of flowchart or a Markov-chain. For more of Nathan’s work, please visit his FlowingData website.