From a coworker at Mural

Each claim has to pass the IRS' 4-part test:

1. Permitted Purpose: The activity must aim (not necessarily succeed) to create or improve functionality, performance, reliability, or quality of a component of the business.
2. Elimination of Uncertainty: At the beginning of the project, there must be technical uncertainty regarding the capability of development, the methodology, or the optimal design.
3. Process of Experimentation: The activities must involve evaluating alternatives—such as modeling, simulation, or systematic trial and error—to resolve the identified technical uncertainties.
4. Technological in Nature: The research process must fundamentally rely on the principles of hard sciences, such as physical or biological sciences, engineering, or computer science.

#1 and #4 are pretty much always a given, and then ICs get called in to audit-proof #2 and #3. The painful part is that our record-keeping is much better at answering questions about outcomes, not the experimental process or all the exploration that never ended up getting shipped.