In 2000 or so, I found the learning pyramid to be devoid of rigorous evidence, consisting primarily of cognitive pollution, and steered the project away from this model. I now find a paper addressing what I was looking at then.
From Excavating the origins of the learning pyramid myths by Kåre Letrud and Sigbjørn Hernes. From the Abstract:
The family of cognitive models sometimes referred to as the ‘Learning Pyramid’ enjoys a considerable level of authority within several areas of educational studies, despite that nobody knows how they originated or whether they were supported by any empirical evidence. This article investigates the early history of these models. Through comprehensive searches in digital libraries, we have found that versions of the Learning Pyramids have been part of educational debates and practices for more than 160 years. These findings demonstrate that the models did not originate from empirical research. We also argue that the contemporary Learning Pyramids, despite their continued modifications and modernizations, have failed to keep up with the developments of cognitive psychology. The conception of memory implied by the Learning Pyramids deviates significantly from the standard picture of human memory.The first few paragraphs are a little more revelatory.
Uncorroborated and even refuted claims about educational psychology and educational neuroscience appear repeatedly in educational studies, practices and debates. It is not uncommon among educators to believe that we use only 10 per cent of the brain, and have different learning styles (for these and other learning myths see Geake, 2008; Goswami, 2006; Howard-Jones, 2014; Kirschner & Merriënboer 2013; Rato, Abreu & Castro-Caldas, 2013). Some of these myths even reach academic status (Kirschner, 2017). This article addresses a similar myth of learning psychology that has circulated widely among educators as well as educational researchers: a family of models that ranks the retention effects from various presentation- and perception modalities. There are several versions of this notion, and those that go by the name of ‘Learning Pyramid’ are probably among the best known. We shall use this as a blanket term for all these different models.This is similar to the history of the Myers-Briggs test which purports to reveal your personality and provide insights into you management style. It is all entertaining nonsense - useful to get teams to talk about styles but unanchored to theoretical efficacy or empirical validity.
We shall present the findings from a search for the original source of these models, and demonstrate that primitive versions were published in the early 1850s. We shall also argue that it is unlikely that the Learning Pyramids originated from empirical studies, because they predate by decades the entire field of experimental retention studies. Furthermore, we shall argue that the current Learning Pyramids are ill suited for research as well as for educational practices. The present-day
Yet, all my professional life, I have attended innumerable training sessions incorporating Myers-Briggs and/or some aspect of the thinking behind Learning Pyramids. It is as if the fact that they are naively plausible is sufficient to go all in for them regardless of empirical integrity.
No use railing against them. Believers gotta believe. But it is a very powerful leading indicator as to whether you are dealing with actually knowledgeable people and institutions or rather are dealing with cognitive followers.