Setting up and learning a note taking or card index system has a reasonably large up-front cost, but learning it well and being able to rely on it over long periods of time will eventually reap larger and cheaper long-term outcomes and benefits.

Unless changing systems creates dramatically larger improvements, the cost of change will surely swamp the benefits making the switch useless. This advice given by Kaiser is still as true today as it was in 1908, we tend not to think about the efficiency as much now as he may have then however and fall trap to shiny object syndrome.

In modern, digital settings, the work of approapriately indexing content is lost in exchange for other forms of organization (tagging, for example), this means one is less reliant on an index for looking up material and more reliant on concordance search of particular words within an ever-growing corpus of collected knowledge.

Over time and with scale, simple tagging may become overwhelming as a search method for finding the requisite material, even when one knows it exists.

As a result a repository may do better in the long run with a small handful of carefully applied rules from the start.

This quote is broadly recognized in economic settings as true, but few in the knowledge management space place emphasis or focus on designing both simple systems which are easy to master and use on a regular, ongoing basis. This allows the knowledge worker the ability to more quickly (almost blindly) handle their indexing and filing operations so that things are precisely where they need them when required for use.

Poor design will not only decrease the ease of use, but also discourage the user from both efficiently using and benefiting from their systems.

Even simple and efficient filing systems require familiarity and expertise for them to effect useful gains to their users, and prove their effectiveness over time. If a user can't get to a basic level of functionality in short time, they're likely to give up on it and never see the ultimate benefits.

Julius Kaiser contemporaneously posits that mass manufacture and maximizing efficiency (greater output for minimum input) are the primary drivers of card index system use in the early 20th century. These also improve both precision and accuracy in handling information which allow for better company or factory operation, which would have been rising concerns for businesses and manufacturing operations at the rise of scientific management during the time period.

Earl Pomeroy suggests that Paxson's note taking method freed his mind to better reflect and appraise his work. This allows a greater efficiency of work, particularly when it comes to easier search and recall as well as the overall process which becomes easier through practice.

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.