Abstract
In recent years, many blog texts are written by common people, many of which are expected to contain naked voices of the authors. Concerning the travel behaviour, we expect that we can study travellers' sentiment by analyzing blog texts for increasing travellers' satisfaction. However, blog texts contain many informal expressions that are not grammatical. Since many of the existing systems of natural language processing are developed with formal texts, they are often weak on informal texts. Moreover, these informal words may be the sentiment that the authors want to emphasize in particular. Therefore, this paper focuses on these informally transformed words. This paper analyzes the transformation patterns of the blog texts about using behaviour of Kansai Airport and reports the customization of a morphological dictionary.