Role of usability studies in the explainer

[js-choi]

Spinning this out of #150, but also some comments in #206, #200, #203, #205, #167, #100, #116, and #154.

Several people have asked for usability studies examining our decision to choose Hack pipes over F# pipes. Mozilla in fact did a usability study in 2018–20 examining smart-mix pipes versus F# pipes, which found that the differences between were very small (in fact, this made the Mozilla SpiderMonkey team weakly against F# pipes and Hack pipes.)

In addition, empiric usability studies are quite rare in PL design and, like all sociological and cognitive studies, are difficult and expensive to perform (we are thankful to Mozilla for funding and performing the one study we do have). TC39 generally is not able to rely on empiric studies but rather must use its representatives’ own expertise from engine implementations, PL design, day-to-day development, and so on.

To emphasize, it is likely than an attempt to switch from Hack pipes to F# pipes will result in TC39 never agreeing to any pipes at all; syntax for partial function application (PFA) is similarly facing an uphill battle in TC39 (see HISTORY.md). I personally think this is unfortunate, and I am willing to fight again for F# pipes and PFA syntax, later—see #202 (comment). But there are quite a few representatives (including browser-engine implementers; see HISTORY.md about this again) outside of the Pipe Champion Group who are against improving tacit programming (and PFA syntax) in general, regardless of Hack pipes.

This is a frequently asked question. The explainer needs to talk about this in an FAQ section.

This issue tracks the fixing of this deficiency in the explainer (lack of documentation regarding usability studies’ role and Mozilla’s prior usability study). Please try to keep the issue on topic (e.g., comments about someone’s personal experiences with either pipe operator to be off topic), and please try to follow the code of conduct (and report violations of others’ conduct that violates it to tc39-conduct-reports@googlegroups.com). Please also try to read CONTRIBUTING.md and How to Give Helpful Feedback. Thank you!