Week 8 Live Session (Fall 2026)

In this week 8 session we answered questions on tidying survey data, then covered converting text to numbers, saving data as RDS, and working with dates. We also looked at fixing common join problems and returned to iteration and writing functions.

You'll learn:

• How to pivot select-all survey columns longer, filter to the yes responses, and count them
• When to use as.numeric() and when to use parse_number() to convert character data
• Why saving a cleaned dataset as RDS keeps factor ordering, while a CSV loses it
• How to fix joins that fail on mismatched variable types or give many-to-many warnings
• How to standardize messy date columns with {lubridate} functions like ymd()

Resources mentioned:

• Claude
• {tidyverse}
• {readr}
• {stringr}
• {lubridate}
• {ggplot2}
• {qualtRics}
• R for Data Science (dates and times chapter)
• Git

Key moments:

• 06:52 Participant question on tidying select-all survey data
• 12:21 Demo: pivot longer, filter to 1s, and count responses
• 16:47 Handling Likert and multiple choice questions in separate data frames
• 18:14 Question on exporting survey data wide or long
• 19:18 Pulling survey data directly into R through an API
• 22:10 as.numeric() versus parse_number()
• 26:37 Using AI to write a regular expression for zip codes
• 28:25 Question on the difference between tibble() and tribble()
• 30:45 Demo: why RDS keeps factors and CSV does not
• 35:05 Working with dates in {lubridate}
• 42:19 Fixing joins with mismatched zip code types
• 46:09 Many-to-many join warning and joining on two variables