That Natural Language Thing

Functional specifications should always be written in a natural language. Why? Well, it's the Sapir-Whorf linguistic relativity hypothesis, don't you know?² In a nutshell, language not only determines what you do say, it determines what you can say (and think). That is, the language you use determines what kinds of thoughts you are able to have, and thus what you can think about and how you express your thoughts. If the language doesn't have room for certain kinds of thoughts, you are much less likely to think them. Natural languages are much more expressive and varied than programming languages, so you want to do your designs in natural languages and save the programming languages for implementation later. Whether you believe the Sapir-Whorf hypothesis or not, it's nearly always a good idea to develop your functional specification in a natural language so you don't get bogged down in the syntactic and semantic details of a programming language before you need to. This doesn't m....³ You might also look at Kenneth Iverson's Turing Award lecture, “Notation as a Tool of Thought,” for a similar discussion.⁴