- Read a datafile in R
- Print summary statistics
- Conduct correlational analyses
- Examine relationships among variables using scatterplots
- Investigating the effects of sport-related concussion
Reading in the data
Correlation analysis of baseline measures
Round to 2 decimal places.
Create two subsets, control and concussedd
Correlation analysis of the control group, all measures. This is test/retest, so we can
test different measures for reliability.
Let’s look at the concussed athletes. We can’t treat this data as test-retest, as there has
been the concussion between the two measurements.
Does baseline impulse control predict memory impairment after a concussion?
Scatterplot functions are available in many packages and offer an array of advanced features. For the sake of time,
I will demonstrate just a few examples here.
Standard scatterplot with regression line. Positive slope means there is a positive correlation.
Scatterplot matrix, in order to plot multiple correlations at once
Colored scatterplot matrix, ordered by magnitude of r
Scatterplots in 3D