Spaced repetition is an entirely different dimension. It doesn't fit between the three mentioned modes. You don't get spaced repetition when e.g. attending class or reading a chapter. Instead, you make notes. That's what this study is for, and anything else is a distraction.
In other words, if your goal is to go fast: a bicycle will outcompete a tricycle. But adding a motor to either will be an order of magnitude better. At least that’s what I think; and so I wish the study had included this.
The implicitions of this study are limited, as usual.
The study in question compared three groups (pen & paper note taking, smartphone and tablet) on information retrieval and note taking duration after reading a dialogue.
Maybe I'm misunderstanding your point, but that systematic spaced repetition will lead to better information retrieval is kind of obvious and has a lot of literature to support it, but how is it relevant to this study?
Judging by the other comments, most people had the same interpretation.
You specifically said that the study was lacking a fourth group (spaced repetition software.)
I used to learn with handwriting more than digital note-taking in the past, but I found it hard to convert the handwritten notes into a flashcard format (the best I could do was retype, or write the notes in a question-answer format, scan them, and use the screenshots as flashcards).
By starting with digital notes, however, the process became simpler for making flashcards for a spaced repetition system—it became much easier to reformat the text for digital flashcards. I then found it much easier to review my notes in the future in a way that actively tested me, versus passively re-reading my handwritten notes.
I can say that SRS reading pales in comparison to SRS writing when it comes to learning Japanese.
i find SRS very useful. but i personally think it is not well suited to reference information. i'm skeptical of putting all my appointments in SRS for example (maybe birthdays would be worth it). or say I had collected a bunch of papers related to a topic I was very interested in. I don't necessarily think I'd want to memorize the list of them via SRS, but having the titles written somewhere for reference would be great. I think the point of this paper is that if that 'somewhere' is an SRS card, it is almost completely devoid of context (other than 'studying flashcards on computer' context), but if that somewhere is a notebook that contains lists of papers related to all the topics i'm interested in, it's much easier to find. (though computers are good at searching fast)
Also, using a SRS in conjunction with a memory palace can solve a lot of the reference issues you’re describing.
Memory palaces are often recommended for reference-type information, so I think this would work well. There are a number of discussions on Art of Memory talking about this:
https://forum.artofmemory.com/t/mind-mapping-memory-techniqu...
https://forum.artofmemory.com/t/anki-to-load-up-a-memory-pal...
You probably mean the confusingly identically named SuperMemo on supermemo.com (not .guru), that is indeed a spaced-repetition software, but is not the venerable and famous real SuperMemo with a gazillion of features and research behind it. Just a simplistic knockoff. Strangely by the same author.
So some information X you want to remember.
It would prompt you with it at 5 minutes, then 20, then an hour, then 5 hours.
I forget the durations, but it was based in some studies on time before short term memory fades.
Then you should go tell the journal editors that this study is incomplete and didn't cover the type of memory you consider more significant, hopefully they will retract the paper