Introduction

  • Organizing your data tables according to tidy data principles will make them easier for you and others to use for analysis.

Formatting Data Tables in Spreadsheets

  • Never modify your raw data. Always make a copy before making any changes.
  • Keep track of all of the steps you take to clean your data.
  • Organize your data according to tidy data principles.
  • Record metadata in a separate plain text file.

Formatting Problems

  • Avoid using multiple tables within one spreadsheet.
  • Avoid spreading data across multiple tabs (but do use a new tab to record data cleaning or manipulations).
  • Record zeros as zeros.
  • Use an appropriate null value to record missing data.
  • Don’t use formatting to convey information or to make your spreadsheet look pretty.
  • Place comments in a separate column.
  • Record units in column headers.
  • Include only one piece of information in a cell.
  • Avoid spaces, numbers and special characters in column headers.
  • Avoid special characters in your data.

Dates as Data

  • Use extreme caution when working with date data.
  • Splitting dates into their component values can make them easier to handle.

Quality Assurance

  • Always copy your original spreadsheet file and work with a copy so you don’t affect the raw data.
  • Use data validation to prevent accidentally entering invalid data.

Exporting Data

  • Data stored in common spreadsheet formats will often not be read correctly into data analysis software, introducing errors into your data.
  • Exporting data from spreadsheets to formats like CSV or TSV puts it in a format that can be used consistently by most programs.