Lab 10: Correlation and Regression

PSY 203: Lab 10.

The primary website for this course is https://faculty.bard.edu/~jdainerbest/psy-203

These are all of the instructions for Lab 10. The list of labs is here.

This website contains R lab code for labs in Bard College’s Fall 2020 for Statistics for Psychology, taught by Prof. Justin Dainer-Best.

You will download the lab’s files to your computer or to your rstudio.cloud account.

Objectives

This lab will walk you through running correlations and regression in R, using functions like cor.test() and cor() for the former and summary() and lm() (linear model) for the latter. You’ll also practice using the {ggplot2} package to create scatterplots with regression lines.

Make sure you’re in the right working directory

Set your working directory if necessary. Check that you’re in the directory you expect by running getwd() in the Console. If you need more help, look at the wiki page on setting a working directory.

Today’s lab

To download and then run the tutorial, run the following two commands. Please note: only run the usethis::usezip() line once! Running it again will result in your overwriting the files on your computer—potentially losing your work.

Make sure you run the whole command, all the way to the closing parenthesis.

usethis::use_zip(paste0("https://github.com/jdbest/",
                        "psy-203/raw/master/lab10.zip"), 
                        cleanup = TRUE)
rmarkdown::run("lab10/correg.Rmd")

Once you’ve completed the tutorial, close it and double click on the correg-exercises.Rmd file in the folder you downloaded. (You may need to close the tutorial window.) To work on the exercises with the tutorial running, refer to the instructions on the wiki.