Getting and Cleaning Data

Course page: https://class.coursera.org/getdata-034 By Jeff Leek, PhD, Roger D. Peng, PhD, Brian Caffo, PhD

• Basic concepts:
  • Find and extract raw data
  • Tidy data principles
  • practical R packages

• Interesting datasets from: https://data.baltimorecity.gov/
• Pipeline: Raw data -> Processing script -> tidy data -> data analysis -> data communication

• Components of tidy data
  • Raw data: can have multiple levels
  • Tidy data
  • Should produce a code book (metadata):
    • could be in markdown
    • should have a section called “Study design” (eg. how raw data was collected)
    • must have section “Code cook”: description of each variable and its units
  • Explicit and exact recipe to go from raw to tidy (instruction list)
    • R script
    • input = raw data, output = processed data
    • no parameter for script