Choosing a graphic form, Fundamental chart types (distributions)

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("naniar") # tools for exploring missing data
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

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

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).

Lab Materials

Lab Slides	Exercise instructions	Exercise solutions
Lab 2 slides: Alt Text	Lab 2 exercise: writing alt text	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