"LOL", "ROFL", and other initialisms have crossed from computer-mediated communication to face-to-face communication. David Crystal—likening the introduction of "LOL", "ROFL", and others into spoken language in magnitude to the revolution of Johannes Gutenberg's invention of movable type in the 15th century—states that this is "a brand new variety of language evolving", invented by young people within five years, that "extendthe range of the language, the expressiveness [and the richness of the language". However Geoffrey K. Pullum argues that even if interjections such as "LOL" and "ROFL" were to become very common in spoken English, their "total effect on language" would be "utterly trivial".