Two recent posts by Geoffrey K. Pullum on Language Log bringing up amusing mistakes in Spanish translated closed captioning (Los Senadores Y El Presidente and Speaking Puerto Rican) got me wondering how exactly closed captioning works and just why the mistakes are often so radically different from what was actually said.

Fortunately, Mark Liberman posted a follow-up explaining in some more detail how stenography and closed captioning works. I had no idea that closed captioning was simply an electronically adapted version of the stenography used in courtrooms, nor just how encoded and abbreviated court stenography was. You can follow the chain of links I did from the posts above, but I recommend you check out these:

• Nice short summary
• A more detailed, very informative explanation with examples
• Mark Liberman's detailed response, with illustrated examples

Now I realize why on TV when a court stenographer is asked to reread a portion of the courtroom transcript, they always have to concentrate and sometimes hesitate while reading. One more bit of useless knowledge crammed into my overflowing bag.