Orthography implicitly influences the trustworthiness of onscreen information in the Japanese language

BACKGROUND: In computer-mediated English-language text on health topics, spelling errors and unorthodox emphasis (e.g. 'shouting' capitalisation) implicitly result in linear and additive penalties to trustworthiness. AIMS: (1) To quantify the effects of misspelling, unorthodox emphasis (boldface text), and their combination on the trustworthiness ratings by native-speaking Japanese laypersons, and to compare these to the analogous effects in English. (2) To compare the trustworthiness ratings between the Japanese and English text of the same statements. METHODS: In an online experiment, ninety-seven Japanese adults rated the trustworthiness (0-100 scale) of 9 brief statements about multiple sclerosis as if presented on an unmoderated health forum. Each statement was randomised into one of four conditions: 5 misspellings, 5 words in boldface text (unorthodox emphasis), the combination of both of those orthographic deviations, or neither. Statistics were assessed using linear mixed effects models. RESULTS: Paragraphs in Japanese that contained any misspellings, were rated significantly less trustworthy compared to the same statements with neither orthographic deviation (p < 0.0001). Furthermore, boldface alone did not elicit a penalty to trustworthiness. In comparing Japanese-speakers to previous data on English-speakers, the English-speakers rated the same text excerpts -8.27 scale-points less trustworthy (p < 0.001). CONCLUSIONS: We conclude that the penalties to trustworthiness of misspelling in Japanese and English were nearly identical. However, unlike for English-speakers, the Japanese unorthodox emphasis we tested (boldface text) did not elicit a penalty to trustworthiness, possibly because no direct equivalent to capitalised 'shouting text' exists in Japanese writing.