S4 versus S3

Which functional object system to use, S3 or S4?

• S3 is a simple and flexible system.

  • Good for small teams who need flexibility and immediate payoffs.

  • Commonly used throughout base R and CRAN

  • Flexibility can cause problems, more complex systems might require formal conventions

• S4 is a more formal, strict system.

  • Good for large projects and large teams

  • Used by Bioconductor project

  • Requires significant up front investment in design, but payoff is a robust system that enforces conventions.

  • S4 documentation is challenging to use.