Reproducibility
The property that a stated result can be regenerated exactly from published inputs and procedure — same data as of the same moment, same code version, same parameters, same output.
The position
Reproducibility in quant research is usually claimed and rarely tested, and the notebook is why. Notebooks execute out of order, hold state invisibly, and pin nothing — the dominant research medium in the field is structurally irreproducible, which almost nobody in the field says out loud. It is also the cheapest governance win available: a result that regenerates on a colleague's machine has passed a harder test than most model validation processes impose.
This section is a claim, not a definition. It is argued rather than asserted, and it is the part of this page you are invited to disagree with. Corrections and counter-arguments to [email protected] are published.