This practice is not too dissimilar to that used by zettelkasten practitioners (including Niklas Luhmann) who broadly used his bibliographic cards this way.

By separating his index and ideas from the book and putting them into a physical index, it makes them easier to juxtapose with other ideas over time rather than having them anchored directly to the book itself. For academics and researchers, this will tend to help save time from having to constantly retrieve these portions from individual books.

I found a way to create order from my jumbled ideas | Writing Slowly<br /> by [[Richard]] on writingslowly.com <br /> accessed on 2025-08-30T19:54:37

The structure of SOLO reminds me of the relationship of Bloom's Taxonomy and zettelkasten: https://boffosocko.com/2022/04/01/the-zettelkasten-method-of-note-taking-mirrors-most-of-the-levels-of-blooms-taxonomy/

https://qnnnp.medium.com/is-a-second-brain-superior-to-no-brainer-writing-c494dc86d429

Dwyer, Edward J. “File Card Efficiency.” Journal of Reading 26, no. 2 (1982): 171–171.

Ease of use in writing and grading with short assignments by using 4 x 6" index cards in classrooms.

This sounds like some of the articles from 1912 and 1917 about efficiency of card indexes for teaching.

I'm reminded of some programmed learning texts that were card-based (or really strip-based since they were published in book form) in the 1960s and 1970s. Thse books had small strips with lessons or questions on the front with the answers on the reverse. One would read in strips through the book from front to back and then start the book all over again on page one on the second row of strips and so on.

Breitenbach, H. P. “The Card Index for Teachers.” The School Review 20, no. 4 (1912): 271–72.

Apparently in 1912, the card index was little known to teachers... this isn't the sort of use case I was expecting here...

The general gist of this short note is an encouraging one to suggest that instead of traditional grade books, which are still used heavily in 2022, teachers should use rolodex like cards for keeping attendance and notes on a student's progress.

Presumably this never caught on. While some elementary teachers still use older paper gradebooks, many others have transferred to digital LMS platforms.