Estimating Numbers without Regression
Avijit Thawani Jay Pujara Ashwin Kalyan
Despite recent successes in language models, their ability to represent
numbers is insufficient. Humans conceptualize numbers based on their
magnitudes, effectively projecting them on a number line; whereas subword
tokenization fails to explicitly capture magnitude by splitting numbers into
arbitrary chunks. To alleviate this shortcoming, alternative approaches have
been proposed that modify numbers at various stages of the language modeling
pipeline. These methods change either the (1) notation in which numbers are
written (\eg scientific vs decimal), the (2) vocabulary used to represent
numbers or the entire (3) architecture of the underlying language model, to
directly regress to a desired number.
  Previous work suggests that architectural change helps achieve
state-of-the-art on number estimation but we find an insightful ablation:
changing the model's vocabulary instead (\eg introduce a new token for numbers
in range 10-100) is a far better trade-off. In the context of masked number
prediction, a carefully designed tokenization scheme is both the simplest to
implement and sufficient, \ie with similar performance to the state-of-the-art
approach that requires making significant architectural changes. Finally, we
report similar trends on the downstream task of numerical fact estimation (for
Fermi Problems) and discuss reasons behind our findings.