Sequence Evaluation using Log-Probability

An engineer is using a generative language model to decide which of two possible sentences is a more likely completion for the input prompt 'Once upon a time,'. The model can compute various log-probability scores. To select the better completion, which of the following scores should the engineer compare for each candidate sentence?

Debugging a Language Model's Output Score

Rationale for Log-Probability Calculation in Generative Models

Core Computational Task in Autoregressive Generation

Step-by-Step Sequence Log-Probability Computation