The Toothbrush Problem

Michael E Gorman, Alexandra Kincannon, Matthew M Mehalik · 2001
from Spherical Horses and Shared Toothbrushes: Lessons Learned from a Workshop on Scientific and Technological Thinking

Taxonomies and frameworks are like toothbrushes — no one wants to use anyone else’s.

The attribution of this quotation is ambiguous. A nice historical overview of the quote can be found in A useless history of the “Frameworks are Like Toothbrushes” quote. While gorman2001 is one of the first appearances of the quote, this metaphor was especially popularized in The Toothbrush Problem by Walter Mischel. Occasionally, it is used in other works (e.g., see elson2023).