The design side of programming language design
IMO, this is  blind spot in the research community right now. The programming language community doesn't care about the ergonomics of language use and is only interested in theoretical evaluation of their work with rigorous proofs.The Human Computer Interaction (HCI) community should care about this, but is beset by two problems: people in PL don't take people in HCI seriously because the people in HCI don't do proofs, and, the people in HCI generally don't have the background to start tackling the mathematical principles of programming language design.This seems like a natural time for some kind of cross discipline collaboration, but the two forces above keep potential collaborators apart. PL people talk about judgements and sub-structural typing and HCI people's eyes glaze over, HCI people talk about human subjects, experimental methodology and statistics and PL people's eyes glaze over.I've advocated for the creation of a new field of study, call it Programmer Computer Interaction. No one takes it that seriously though, and the intersection of researchers that care simultaneously about things like good experimental design, statistical significance, type theory and constructive logic seems to be just me.