Entropy of Ukrainian

arXiv cs.CL / 5/1/2026

📰 NewsModels & Research

Key Points

  • The paper studies the character-level entropy (unpredictability/complexity) of the Ukrainian language using a next-character prediction experiment.
  • It is the first reported attempt to run Shannon-style entropy estimation for Ukrainian, recruiting 184 volunteers via social media.
  • Using techniques adapted from prior English work, the authors estimate an upper bound of Ukrainian entropy at about 1.201 bits per character.
  • The study compares the measured entropy bound with the performance of current large language models.
  • Methods and code are released publicly, along with discussion of key challenges in running the experiment for Ukrainian.

Abstract

In natural language processing, the entropy of a language is a measure of its unpredictability and complexity. The first study on this subject was conducted by Claude Shannon in 1951. By having participants predict the next character in a sentence, he was able to approximate the entropy of the English language. Several follow-up studies by other authors have since been conducted for English, and one for Hebrew. However, to date, Shannon's experiment has never been conducted for Ukrainian. In this paper, we perform this experiment for Ukrainian by recruiting 184 volunteers using social media channels. We rely on techniques used for English to approximate the entropy value of Ukrainian. The final result is an upper bound of H_{upper}\approx1.201 bits per character. We compare this to the performance of current Large Language Models. The methods and code used are also documented and published, along with a discussion of the main challenges encountered.