Correcting Low-Signal Sensitivity in the Deliberative Reason Index

Abstract

The Deliberative Reason Index (DRI) is increasingly used to assess the coherence between considerations and preferences in deliberative settings, including applications to LLM-generated data. Under low-signal conditions, however, the standard DRI can produce inflated scores by treating near-zero correlations as evidence of consistency. Monte Carlo simulations across common study designs show that this bias increases with group size and yields positive values even under random response. A modified DRI is introduced that applies a continuous penalty to low-signal correlation pairs. The modification preserves the original scale and reduces exactly to the standard DRI when substantive signal is present. A threshold sensitivity analysis identifies {\tau}=0.2as the optimal parameter. An empirical check with archival deliberative data shows that substantive inferences remain unchanged. The modification improves the reliability and comparability of the DRI in low-signal settings.