CONCEPT
Independence Ratio
The Bruner volume's proposed diagnostic metric — the relationship between what a builder can accomplish with AI and what the same builder can accomplish without it — and the measurement that separates scaffolding from prosthesis.
The independence ratio is the measurement Bruner's framework demands that the AI discourse does not perform. Productivity multipliers measure the scaffold's power. Adoption rates measure the scaffold's reach. Revenue measures the scaffold's market value. None measure what scaffolding is supposed to produce: the learner's growth. The independence ratio measures exactly that. If a builder's unaugmented capability rises toward her augmented capability over time, the scaffold is functioning as scaffolding — building internal capacity through supported practice. If unaugmented capability stagnates or declines while augmented capability soars, the scaffold is functioning as prosthesis — expanding the appearance of capability while leaving underlying development unchanged. No major study has measured the independence ratio. The metrics that dominate all measure scaffolded performance. Independent capability, the thing Bruner's framework identifies as the purpose of scaffolding, remains unmeasured.
In The You On AI Field Guide
The ratio is empirically simple but practically uncomfortable. Measuring it requires removing the scaffold and observing what the builder can