An OCI GenAI model generates English to French translation. Which metric is most appropriate to evaluate its quality?
BLEU is the standard metric for translation tasks.
Why this answer
BLEU (Bilingual Evaluation Understudy) is the standard metric for machine translation tasks because it measures the n-gram overlap between the generated translation and one or more reference translations, directly assessing fluency and adequacy. For English-to-French translation, BLEU correlates well with human judgment of translation quality, making it the most appropriate choice.
Exam trap
Oracle often tests the distinction between metrics for generation tasks (BLEU for translation, ROUGE for summarization, perplexity for language modeling) and classification metrics (F1 score), leading candidates to confuse their appropriate domains.
How to eliminate wrong answers
Option A is wrong because perplexity measures how well a language model predicts a sequence of tokens, not the quality of a translation against a reference. Option B is wrong because ROUGE is designed for summarization tasks, focusing on recall of n-grams and longest common subsequences, not translation accuracy. Option C is wrong because F1 score is a classification metric (precision and recall) that does not capture the sequential and lexical alignment required for evaluating translation output.