It was the birth of a new approach to linguistics - At the time COBUILD began (1980s/1990s) 'computational linguistics' required a large bank of people doing the work of finding the 'words' in their context. Now, with the internet as it is, computer power and algorythms so common, it's hard to imagine a time before (without the help of youtube).
John Sinclair worked on 'collocation' and 'cooccurance' - where and when words occur, with which other ones, and why - led to the COBUILD Dictionary, printed on paper. Now even the concept of a paper dictionary seem old hat - how can a dictionary remain up-to-date, if it's printed more than a year ago? Is it because now we demand the 'latest' word meanings, or that language is developing faster?
At the time (the early 1990s) I remember lively discussions on how heavily weighted the meanings of words should be based on the opinions of 'experts', and how much on their current usage - this argument, in linguistic terms, seems old hat.
John Sinclair's legacy has been huge, and is alive and well, if mainly online.
Part of #29daysofwriting @staffrm