Broadening these concepts beyond simple physical interpretations has provided a starting point for addressing the complex and dynamic nature of human communication.
In his Source-Message-Channel-Receiver model, David Berlo identified skills specific to encoding. His two decoding skills are speaking and writing. His two decoding skills are listening and reading. Berlo also identified a fifth skill-thought or reasoning. This fifth skill is essential to both encoding. These five communication skills can be present in the source and receiver to varying degrees.