Others have argued that mutual intelligibility occurs in varying degrees, and the potential difficulty in distinguishing between intelligibility and prior familiarity with the other variety. However, recent research suggests that there is some empirical evidence in favor of using some form of the intelligibility criterion to distinguish between languages and dialects, though mutuality may not be as relevant as initially thought. The requirement for mutuality is abandoned by the Language Survey Reference Guide of SIL International, publishers of the Ethnologue and the registration authority for the ISO 639-3 standard for language codes. They define a dialect cluster as a central variety together with all those varieties whose speakers understand the central variety at a specified threshold level or higher. If the threshold level is high, usually between 70% and 85%, the cluster is designated as a language.
Others have a.rgued that mutual intelligibility occurs in varying degrees, and the potential difficulty in distinguishing between intelligibility and prior familiarity with the other variety. However, recent research suggests ,that there is some empirical evidence in fav.or of using some form of the intelligibility criterion to distinguish between languages and dialects though mutuality may not be a?s relevant as initially thought The requirement for mutuality is abandoned by the Language Survey Reference Guide of SIL International, publishers of the Ethnologue and the registration authority for the ISO 639-3 standard for language codes. They define a dialect cluster as a central variety together with all those varieties whose speakers understand the central variety at a specified threshold level or higher. If the threshold level is high, usually between 70% and 85%, the cluster is designated as a language.