Choosing a graphic form, Fundamental chart types (distributions)

Week 2

Wednesday January 14th, 2026

A formula for writing alternative text, which says you should always include (a) the chart type, (b) the type of data being presented, and (c) the reason for including the chart. You should also link to the data source somewhere in the text.

Image from Amy Cesal’s article, Writing Alt Text for Data Visualization, published in Nightingale. You’ll practice writing alt text in this week’s lab session.

Pre-class Prep

A. Install required packages

install.packages("chron") # for working with dates / times
install.packages("ggridges") # {ggplot2} extension for creating ridgeline plots
install.packages("gghighlight") # {ggplot2} extension for highlighting geoms
install.packages("ggbeeswarm") # {ggplot2} extension for creating categorical scatter (violin point) plots

B. Download data

Save data to your class repo at EDS-240-class-examples/week2/data/:

Lecture Dataset title Download link Notes
2.2 SBC LTER: Ocean: Currents and Biogeochemistry: Moored CTD and ADCP data from Mohawk Outside Spar (MKO), ongoing since 2005 download from the EDI Data Portal by clicking the “Download” button (Google Drive backup link, in case EDI is down) Data collected by the Santa Barbara Coastal Long Term Ecological Research (SBC LTER) site

C. Download .qmd templates & review initial data wrangling code

  1. Download all necessary templates (links in the table below) and save them to a EDS-240-data-viz-examples/week2/ folder.

  2. Review the data wrangling code under the ## Setup section of each template file and make note of any questions you might have. Due to time constraints, we won’t be live-coding our way through the data wrangling code in class. However, we’ll reserve some time to answer any questions before we jump into data viz .

Lecture Materials

Lecture slides Code-along template Code-along key
Lecture 2.1: choosing graphic form NA NA
Lecture 2.2: visualizing distributions 2.2 template 2.2 key

Pre-lab Prep

TODO
  • new lab content should include writing alt text (currently linked to week 3) + finding data (for FPM #1)

A. Prepare a week2-lab.qmd file

Add a new blank file to your class repo at the following location: EDS-240-class-examples/week2/week2-lab.qmd. Fill out the necessary YAML information (title, author, date + any other information you find helpful).

B. (OPTIONAL) Install Chrome extension for picking colors

Install the ColorZilla Google Chrome extension (also available for Firefox), which makes it easy to select color values from webpages.

Lab Materials

Lab Slides Exercise instructions Exercise solutions
Lab 2 slides: USDM Lab 2 exercise: recreate USDM viz Lab 2 solution

Assignment Reminders

Assignment Type Assignment Title Date Assigned Date Due
HW Homework Assignment #1 Wed 01/07/2026 Wed 01/14/2026, 11:59pm PT
FPM Final Project Milestone #1 Wed 01/14/2026 Wed 01/21/2026, 11:59pm PT