Lexical predictors of text complexity: The case of Russian as a foreign language

Abstract

The article presents results of a comparative analysis of lexical complexity of educational texts in teaching Russian as a foreign language. The corpus size of the study is about 0.5 million words evenly distributed among six levels of language proficiency (A1-C2, Russian National System of Certification Levels of General Proficiency in Russian as a Foreign Language, further – RNSCL). The analysis algorithm is demonstrated based on B2 level texts, for which we estimated the values of the eight complexity predictors using the automatic analyzers RuLex (rulex.kpfu.ru) and RuLingva (rulingva.kpfu.ru): the number of tokens and types, sentence length, word length, lexical diversity (LD), terminological density, readability (MSIS) and frequency. B2 texts demonstrate significant differences in all the parameters, except for the word length. The validated B2 average word length is 2.26 syllables. The increase of lexical diversity from A1 to C2 is insignificant being within the range of 0.3 - 0.5. The complexity growth in RFL texts is accompanied by an increase of terminological density and the readability index. Since the RFL text is an important source of linguocultural information, the research findings may be useful to researchers, developers of educational resources and test materials, and teachers for text selection processes.