Filter 3: Interference
…or what currently affects the message object
When someone tries to corrupt the object of a message, it is considered voluntary interference. When someone or something interferes without the intent to do so, it is called involuntary interference.
We sometimes discern overt interference, as when a car salesman praises a new model by amplifying its qualities. Involuntary interference is, however, by far the most common.
The best way to understand interference is to think of it in terms of focussed vs. peripheral vision. When you are watching television, you are focussed on the main message: the TV screen and its content. We cannot, however, analyze that TV message without taking into account the room or even the room next door. Interference can, in fact, stretch quite far. Watching a crime show while sitting in your safe neighborhood is not the same as watching it while staying at a distant hotel in an unsafe neighborhood, city or country. That unsafe environment will add a high degree of anxiety and influence how you interpret the show.
Another, more dangerous form of interference, is covert interference. The most disreputable manifestation is subliminal advertising. Other, more subtle covert methods are as dangerous. Retailers use these tactics regularly. They want you to follow a certain itinerary or stop at certain key junctions in their store; there are several ways of getting you to do so without your knowledge. I have seen success rates as high as 90% using these subliminal tactics.
In communications analysis, interference is more often a mathematically negative value — it counter-balances positive message values.