GIGO
acronymprogrammingops culture
Stands for: garbage in, garbage out
Garbage in, garbage out: no computation improves the quality of its inputs.
The phrase dates to computing's earliest decades, answering the public's faith that machines could not be wrong: they compute exactly, including exactly wrong answers from wrong data. It survived every technology shift and gained new force in the machine-learning era, where the garbage is the training set. Data validation, pipelines, and model cards are all GIGO taken seriously.