How do we make programming languages more usable and learnable?

Amy Ko made a fascinating claim recently, “Programming languages are the least usable, but most powerful human-computer interfaces ever invented” which she explained in a blog post.  It’s a great argument, and I followed it up with a Blog@CACM post, “Programming languages are the most powerful, and least usable and learnable user interfaces.”

How would we make them better?  I suggest at the end of the Blog@CACM post that the answer is to follow the HCI dictum, “Know thy users, for they are not you.”

We make programming languages today driven by theory — we aim to provide access to Turing/Von Neumann machines with a notation that has various features, e.g., type safety, security, provability, and so on.  Usability is one of the goals, but typically, in a theoretical sense.  Quorum is the only programming language that I know of that tested usability as part of the design process.

But what if we took Amy Ko’s argument seriously?  What if we designed programming languages like we defined good user interfaces — working with specific users on their tasks?  Value would become more obvious.  It would be more easily adopted by a community.  The languages might not be anything that the existing software development community even likes — I’ve noted before that the LiveCoders seem to really like Lisp-like languages, and as we all know, Lisp is dead.

What would our design process be?  How much more usable and learnable could our programming languages become?  How much easier would computing education be if the languages were more usable and learnable?  I’d love it if programming language designers could put me out of a job.