Sampling is a labor-saving device

Last month I wrote those words on a slide I was preparing to show to the American Association for Corpus Linguistics, as a part of a presentation of my Digital Parisian Stage Corpus. I was proud of having a truly representative sample of theatrical texts performed in Paris between 1800 and 1815, and thus finding a difference in the use of negation constructions that was not just large but statistically significant. I wanted to convey the importance of this.

I was thinking about Laplace finding the populations of districts “distributed evenly throughout the Empire,” and Student inventing his t-test to help workers at the Guinness plants determine the statistical significance of their results. Laplace was not after accuracy, he was going for speed. Student was similarly looking for the minimum amount of effort required to produce an acceptable level of accuracy. The whole point was to free resources up for the next task.

I attended one paper at the conference that gave p-values for all its variables, and they were all 0.000. After that talk, I told the student who presented that those values indicated he had oversampled, and he should have stopped collecting data much sooner. “That’s what my advisor said too,” he said, “but this way we’re likely to get statistical significance for other variables we might want to study.”

The student had a point, but it doesn’t seem very – well, “agile” is a word I’ve been hearing a lot lately. In any case, as the conference was wrapping up, it occurred to me that I might have several hours free – on my flight home and before – to work on my research.

My initial impulse was to keep doing what I’ve been doing for the past couple of years: clean up OCRed text and tag it for negation. Then it occurred to me that I really ought to take my own advice. I had achieved statistical significance. That meant it was time to move on!

I have started working on the next chunk of the nineteenth century, from 1816 through 1830. I have also been looking into other variables to examine. I’ve got some ideas, but I’m open to suggestions. Send them if you have them!

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