The recent performance leap of Large Language Models (LLMs) opens up new
opportunities across numerous industrial applications and domains. However,
erroneous generations, such as false predictions, misinformation, and
hallucination made by LLMs, have also raised severe concerns for the
trustworthiness of LLMs', especially in safety-, security- and
reliability-sensitive scenarios, potentially hindering real-world adoptions.
While uncertainty estimation has shown its potential for interpreting the
prediction risks made by general machine learning (ML) models, little is known
about whether and to what extent it can help explore an LLM's capabilities and
counteract its undesired behavior. To bridge the gap, in this paper, we
initiate an exploratory study on the risk assessment of LLMs from the lens of
uncertainty. In particular, we experiment with twelve uncertainty estimation
methods and four LLMs on four prominent natural language processing (NLP) tasks
to investigate to what extent uncertainty estimation techniques could help
characterize the prediction risks of LLMs. Our findings validate the
effectiveness of uncertainty estimation for revealing LLMs'
uncertain/non-factual predictions. In addition to general NLP tasks, we
extensively conduct experiments with four LLMs for code generation on two
datasets. We find that uncertainty estimation can potentially uncover buggy
programs generated by LLMs. Insights from our study shed light on future design
and development for reliable LLMs, facilitating further research toward
enhancing the trustworthiness of LLMs.Comment: 20 pages, 4 figure