Might also be worth looking into the work on Statistically Improbably Phrases, which tends to use tf-idf.
https://en.wikipedia.org/wiki/Statistically_improbable_phrase (potentially promising reading in the references for this article)

-marijane

From: Code for Libraries <[log in to unmask]> on behalf of "Stuart A. Yeates" <[log in to unmask]>
Reply-To: Code for Libraries <[log in to unmask]>
Date: Friday, July 10, 2020 at 1:40 PM
To: "[log in to unmask]" <[log in to unmask]>
Subject: Re: [CODE4LIB] to stop word, or not to stop word. that is the question

Sounds like a classical use for the  tf–idf measure.

For those with no background in information retrieval, see
https://en.wikipedia.org/wiki/Tf%E2%80%93idf

cheers
stuart

--
...let us be heard from red core to black sky

On Sat, 11 Jul 2020 at 06:58, Eric Lease Morgan <[log in to unmask]<mailto:[log in to unmask]>> wrote:

To stop word, or not to stop word? That is the question.

Seriously, I am working with a team of people to index and analyze a set of 65,000 - 100,000 full text scientific journal articles, and all of the articles are on the topic of COVID-19. [1] We have indexed the data set and we have created subsets of the data, affectionately called "study carrels". Each study carrel is characterized with a short name and a few bibliographic-like features. [2] Within each study carrel are a number of different analyses, such as ngram frequencies, parts-of-speech enumerations, and topic modeling.

Each article in each carrel also has a set of "keywords" extracted from it. These keywords are computed, and for all intents & purposes, the computation is pretty good. For example, see a set of keywords from a particular carrel. [3] Unfortunately, many of the study carrels have very very very similar sets of keywords. Again, if you peruse the set of all the carrels [2] you see the preponderance of keywords such as "cell", "covid-19", "SARS", and "patient". These words happen so frequently that they become (almost) meaningless.

My questions to y'all are, "When and where should I add something like 'cell', or better yet 'covid-19', to my list of stopwords?"


[1] data set of articles - https://www.semanticscholar.org/cord19
[2] study carrels - https://cord.distantreader.org/carrels/INDEX.HTM
[3] example keywords - https://cord.distantreader.org/carrels/kaggle-risk-factors/index.htm#keywords

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Eric Morgan