篇名 | Extension of Zipf's Law to Word and Character N-grams for English and Chinese |
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卷期 | 8:1 |
作者 | Ha, Le-quan 、 Sicilia-Garcia, E.-I. 、 Ming, Ji 、 Smith, F.-J. |
頁次 | 077-101 |
關鍵字 | Zipf 's law 、 n-grams 、 Chinese compound word 、 Chinese character 、 phrases 、 THCI Core |
出刊日期 | 200302 |
It is shown that for a large corpus, Zipf 's law for both words in English and characters in Chinese does not hold for all ranks. The frequency falls below the frequency predicted by Zipf's law for English words for rank greater than about than about 1,000. However, when single words or characters are combined together with n-gram words or characters in one list and put in order of frequency, the frequency of tokens in the
combined list follows Zipf’s law approximately with the slope close to -1 on a loglog plot for all n-grams, down to the lowest frequencies in both languages. This behaviour is also found for English 2-byte and 3-byte word fragments. It only happens when all n-grams are used, including semantically incomplete n-grams. Previous theories do not predict this behaviour, possibly because conditional probabilities of tokens have not been properly represented.