The utility of retrieval augmented generation (RAG) systems is actively being explored across a wide range of domains. Reliable generative output is increasingly useful in fields where routine tasks can be streamlined and potentially improved by integrating domain-specific data in addition to individual expert knowledge, such as medical care. To that end, we present a hybrid RAG and GraphRAG user interface system to summarize the key information (KI) section in IRB informed consent documents. KI summaries are a unique task, as generative summarization helps the end user (clinical trial expert) but can pose a risk to the affected user (potential study participants) if inaccurately constructed. Thus, the KI summarization task requires reliable, structured output with input from an expert knowledge source outside of the informed consent document. Reviewed by IRB domain experts and clinical trial PIs, our summarization application produces accurate (70% to 100% varied by accuracy type) and useful summaries (63% of PIs stating summaries were as good as or better than their accepted summaries).

Reliable uncertainty quantification (UQ) is essential for ensuring trustworthy downstream use of large language models, especially when they are deployed in decision-support and other knowledge-intensive applications. Model certainty can be estimated from token logits, with derived probability and entropy values offering insight into performance on the prompt task. However, this approach may be inadequate for probabilistic scenarios, where the probabilities of token outputs are expected to align with the theoretical probabilities of the possible outcomes. We investigate the relationship between token certainty and alignment with theoretical probability distributions in well-defined probabilistic scenarios. Using GPT-4.1 and DeepSeek-Chat, we evaluate model responses to ten prompts involving probability (e.g., roll a six-sided die), both with and without explicit probability cues in the prompt (e.g., roll a fair six-sided die). We measure two dimensions: (1) response validity with respect to scenario constraints, and (2) alignment between token-level output probabilities and theoretical probabilities. Our results indicate that, while both models achieve perfect in-domain response accuracy across all prompt scenarios, their token-level probability and entropy values consistently diverge from the corresponding theoretical distributions.