Here is the audio/transcript from the trading floor during the 9 minute Flash Crash -- http://www.protranscript.com/Flash_Crash It gets interesting around 2:30

I'm trying to understand the difference between an interactive transcript, as seen at protranscript.com, and a caption. Why did Google go the embedded captioning route? Isn't the goal to create searchable content? If so, captions don't seem to be the solution.