Information Operations (IO) is improperly defined by most as being technical in nature. It is not. Properly understood, IO should cover the totality of information in all its forms, and Human Intelligence (HUMINT) is the primary player. Below is a fine CRS report on this topic from an electronic point of view.
The Special Operations Command (SOCOM) gets it. They like to say:
“Secret intelligence is 10% of all-source intelligence; and all-source intelligence is 10% of Information Operations.”
Below are links to our HUMINT article and to the book on INFORMATION OPERATIONS: All Information, All Languages, All the Time.