Assignment 1: Getting Started with R

Due by 11:59 PM on Sunday, April 5, 2026

NoteAssignment Details

Assigned: Wednesday, April 1 (Session 2) Due: Sunday, April 5 at 11:59 PM Submit: R script (.R file) on Canvas

TipNew to R?

See the step-by-step guides: Setting Up an R Project | Using R Scripts

Overview

This assignment gets you comfortable with RStudio and introduces you to creating visualizations with ggplot2. You’ll work with the built-in mpg dataset to create your first plots.

Setup

  1. Open RStudio and your psy410 project
  2. Create a new R script: File → New File → R Script
  3. Save it as assignment-01-YOURNAME.R
  4. At the top of your script, add:
# Assignment 1: Getting Started with R
# Your Name
# Date

library(tidyverse)

Tasks

Task 1: Explore the data (10 points)

Use the mpg dataset (loaded automatically with tidyverse).

  1. Use glimpse() to look at the structure of mpg. In a comment, note how many rows and columns there are.

  2. Use ?mpg to read the documentation. In a comment, explain what displ and hwy represent.

Task 2: Create a basic scatterplot (15 points)

Create a scatterplot showing the relationship between engine displacement (displ) and highway fuel efficiency (hwy).

Your plot should:

  • Have displacement on the x-axis
  • Have highway mpg on the y-axis
  • Include a clear title
  • Have labeled axes (not just variable names)

Task 3: Add color (20 points)

Modify your scatterplot to color the points by vehicle class (class).

  • The legend should appear automatically
  • Give the legend a clear title (hint: use labs())

Task 4: Create faceted plots (20 points)

Create the same scatterplot (displacement vs highway mpg, colored by class), but now faceted by drive type (drv).

  • Use facet_wrap()
  • Each panel should be clearly labeled

Task 5: Save your plot (15 points)

Save your final faceted plot as a PNG file.

ggsave("mpg_faceted_plot.png", width = 10, height = 6)

Verify the file was created in your project folder.

Task 6: Reflection (10 points)

At the bottom of your script, answer these questions in comments:

# Reflection Questions:
# 1. What relationship do you observe between engine size and fuel efficiency?
# 2. Do all vehicle classes follow the same pattern?
# 3. What was the most challenging part of this assignment?

Submission Checklist

Before submitting, make sure:

Submit your .R file on Canvas.

Grading Rubric

Task Points
Task 1: Data exploration 10
Task 2: Basic scatterplot 15
Task 3: Color mapping 20
Task 4: Faceting 20
Task 5: Saving plot 15
Task 6: Reflection 10
Code runs without errors 10
Total 100