In theory, this is much like using a French to English dictionary. The captioners' dictionaries contain steno entries with English definitions. That translated word is then sent via modem to an encoder at the television studio where each word is then encoded into line 21 of the broadcast signal. Next, the encoded words are decoded at the viewer's television set while they are watching the program. All this occurs within a few seconds of the word being said on the program.
Captions are useless to the viewer if they lag far behind or are full of errors.
Sometimes you will notice errors with realtime captioning. This is due to the fact that each word, as translated, is sent out with very little room for correction. As well, other factors like the speed of a program and unique words may also cause incorrect words or spellings to appear. All information contained herein is copyright of The Captioning Group Inc. and cannot be used in any publication or distributed in any manner whatsoever without the express written permission of The Captioning Group Inc .