6.1 Philosopy/Principles
There are three interrelated rules which make a dataset according to this philosophy tidy:
- Each variable must have its own column.
- Each observation must have its own row.
- Each value must have its own cell.

Figure 6.1: Three rules make a dataset tidy: variables are in columns, observations are in rows, and values are in cells
For more information, see the ‘Tidy Data’ chapter of the book ‘R for Data Science’" and the ‘Tidy Data’ paper published in the ‘Journal of Statistical Software’".