If we can agree that the practice of data science is about extracting value out of data, then it’s clear that the primary foundation for the practice is efficiency.
Yield in any given activity may be achieved by having an outcome that drives a gain greater than it costs to arrive at the outcome. That means yield can be improved by the means of a better outcome, or a lower cost to arrive at that outcome. The other is the external and other is the internal.
It is typical that the external is more or less a zero-sum game, where as the internal is not. It is from the internal that the external arise.