Construction and analysis of a corpus of Japanese textbooks as a basis for the development of a readability measurement tool for learners of Japanese as a foreign language

Abstract

Readability assessment is a useful procedure when writing, editing or selecting texts for weak readers. Tools which have recently been developed for the assessment of Japanese text readability for native speakers are tested on a corpus of Japanese textbooks and found to be only partially applicable to readability assessment for foreign learners. Two factors are measured in the same corpus: average sentence length is found to be a reliable predictor of text difficulty, while character type-token ratio is not as successful.