Apparent Time and Real Time Studies of Language Change
Language change and the mechanics of language change are investigated by apparent time studies and real time studies of language change which differ from each other in the way they approach the detection of language change in a speech community.
Apparent time studies of language change focus on a comparison between the speech patterns of different age groups (i.e. younger and older speakers) within the same speech community at a certain moment in time. If younger speakers show linguistic differences to older speakers in a speech community, this can be interpreted as an indication of linguistic change taking place in this community. However, in the course of such a comparison it is important to make a distinction between linguistic differences that are based on speaker age (thus due to the stable variable of age-grading) and differences that truly reflect language change in progress.
Real time studies of language change focus on detecting change not in apparent time but in real time. The speech of different age groups is compared at different moments in time in order to detect historical change in the community, i.e. to find out about linguistic change in a community as it progresses through time. Language change in real time can be illustrated by the repetition of a community study. That is, the linguistic variation in a speech community is reinvestigated in a new study undertaken after a certain amount of time. Significant deviations from the originally found speech patterns within this community are interpreted as signs of linguistic change over time.