tidyr 1.0: gather() and spread() are dead

{tidyr} version 1.0 has just been released on CRAN in September 2019, 5 years after it’s conception in Hadley Wickham’s seminal Tidy Data paper. While {tidyr} might not get as much love as {dplyr} and Hadley’s other packages, it’s the cornerstone of the tidyverse and this new version of the package radically changes things.

There’s a new {tidyr} vignette about these “pivoting” functions which explains very simply why these old functions have been retired and replacements created:

there is something fundamentally wrong with the design of spread() and gather(). Many people don’t find the names intuitive and find it hard to remember which direction corresponds to spreading and which to gathering. […] meaning that many people (including [Hadley Wickham]) have to consult the documentation every time.

I’m extremely happy about these changes, the new functions are tremendously flexible and nicely named.

But, I also have the following concerns:

• It will take several years before these new functions permeate StackOverflow, blogs and the wider useR community.
  Self-taught users (like myself) are more likely to copy and paste from StackOverflow than from the docs. These users will likely completely miss out on the new functions and feel frustrated in the future at having learned out-dated practices.

• gather() and spread() aren’t actually dead, they’ve just been retired.
  I started learning R in May 2015 and had a thoroughly bastardised workflow involving {plyr}, {dplyr} and subset() because (seemingly) most folks didn’t realise that {dplyr} was a replacement for {plyr}. I’m confident that we’ll see Frankensteinian combinations of the old and new functions.

• What do we do with our existing training materials?
  Should we update all our old training courses or trust users to find the documentation/vignette eventually?

To help decide how to approach updating our own courses, I put together the following Twitter poll (which received 196 votes!):

I was quite shocked that just under 50% of respondents were planning to update their training courses immediately, and discouraged that my initial choice - waiting until January 2020 - was the least popular response. However, if the community does move quickly to update their content then the concerns I raised above will have much less of an impact than I feared.