SLoW: Select Low-frequency Words! Automatic Dictionary Selection for Translation on Large Language Models

There are more than 7,000 languages around the world, and current Large Language Models (LLMs) only support hundreds of languages. Dictionary-based prompting methods can enhance translation on them, but most methods use all the available dictionaries, which could be expensive. Instead, it will be flexible to have a trade-off between token consumption and translation performance. This paper proposes a novel task called Automatic Dictionary Selection (ADS). The goal of the task is to automatically select which dictionary to use to enhance translation. We propose a novel and effective method which we call Select Lowfrequency Words! (SLoW) which selects those dictionaries that have a lower frequency. Our methods have unique advantages. First, there is no need for access to the training data for frequency estimation (which is usually unavailable). Second, it inherits the advantage of dictionary-based methods, where no additional tuning is required on LLMs. Experimental results on 100 languages from FLORES indicate that SLoW surpasses strong baselines, and it can obviously save token usage, with many languages even surpassing the translation performance of the full dictionary baseline. 12 * Equal Contribution. Ground-truth Tsonga Muteki wa swifaniso u tleketliwile ku ya le Ronald Reagan UCLA Medical Center, laha a fikeke a fa. Ground-truth English The photographer was transported to Ronald Reagan UCLA Medical Center, where he subsequently died. Vanilla Model COMET Score: 0.579 ✗ "Ambulance from Ronald Reagan UCLA Medical Center has arrived." Differ in Round-trip COMET Score: 0.413 ✗ The ensued entertainment after Ronald Reagan UCLA Medical Centre called the police but attempted him for throad and for traffic stop due to him driving too fast therefore prompting visual imagery for the first time in South Africa. Differ in Translation COMET Score: 0.335 ✗ The driver of the police vehicle had his ear given according to the witness who is accused of not being prepared to pay a fine. Noun Dictionary COMET Score: 0.806 ✗ The person in the photographs was taken to the Ronald Reagan UCLA Medical Center, where he died. Adjective Dictionary COMET Score: 0.562 ✗ Ronald Reagan Center where he died. Noun and Adjective Dictionary COMET Score: 0.763 ✗ The driver of the vehicle was taken to Ronald Reagan UCLA Medical Center, where he died. Noun, Adjective, and Verb Dictionary COMET Score: 0.864 ✗ The photographer was taken to the Ronald Reagan UCLA Medical Center, where he died. High-frequency COMET Score: 0.707 ✗ The man of images was taken to the Ronald Reagan UCLA Medical Center, where he died. SLoW COMET Score: 0.912 ✓ The photographer was transported to the Ronald Reagan UCLA Medical Center, where he subsequently died.