Data scientist Cathy O’Neil has written that “models are opinions embedded in mathematics.”8 Models are useful because they let us strip out extraneous information and focus only on what is most critical to the outcomes we are trying to predict. But they are also abstractions. Choices about what goes into them reflect the priorities and preoccupations of their creators. Human decision-making is reflected in three key components of the AFST: outcome variables, predictive variables, and validation data.
