The communication path starts with the sender and ends with the receiver. As soon as the message leaves the sender's mind (a process called encoding), it travels the channel. The moment it arrives in the receiver's mind (a process called decoding), it leaves the channel again. See Figure 1 above.

Channels vary considerably. Pen and paper, and postal services are obvious examples in written communication, telephone lines and the air in spoken communication. Electronic channels like PCs and e-mail are extremely important these days in written business communication.

In communication many things can go wrong. The writer may write down things wrongly or may be unclear, the speaker may not phrase things clearly or correctly: this is called internal interference. External interference is anything from outside that prevents the message (in itself correct) from reaching the receiver correctly.

2.1 Internal Interference

Internal interference happens when the sender puts his message wrongly on the communication path. He may, for example, make grammatical, spelling or pronunciation mistakes that cause the receiver to misinterpret the message. He may also construct his sentences in such a way, that they can be interpreted in more than one way. This may result in the receiver decoding a message differently from how the sender encoded it.

This happens, for example, when a sender writes an email too quickly without thinking carefully. It also happens frequently in all sorts of spoken communication: speakers are very often unclear and are then asked to explain things differently. Since the sender is the cause of internal interference, he is the only one able to prevent it.

2.2 External Interference

Messages can become corrupted by outside influences in a wide variety of ways.

External interference with written messages is caused by anything that happens to it on its way from sender to receiver. A few examples: a letter may become wet in the rain, so that part of it becomes unreadable. An email server may go down, so that an email simply does not arrive. Usually there is little the sender can do about this. Feedback from the receiver may prompt him to quickly send another message.

But the receiver himself may also cause external interference. For example, he finds it impossible to concentrate, or he is bored with the subject of the message. This may happen to written messages as well as to spoken ones. Examples are easy to list: uninteresting articles and e-mails, boring discussion items in meetings, monotonous presentations, a business partner you dislike, or, simply, Monday morning blues.

A few more examples of external interference in oral communication are the following. Fellow participants in a meeting may start a private conversation. Audience members in a presentation may leave the room. People in the same room that you are conducting a business interview in start talking. In all these three sorts of spoken communication there may be lots of noise from outside, for example, from traffic, construction work, etc. Usually there is little the sender can do to prevent this. Feedback from receivers may help here, too.

Conclusion

The sender's/writer's/speaker's aim is always to get his whole message across as accurately as possible. At the same time, it is in the receiver's/reader's/listener's interest to decode the full message the way the sender intended it. This interaction between sender and receiver is vital in any communication process.

There is, obviously, a lot more to be said about communication theory. It is hoped, however, that students will communicate more effectively with the information above, if only because they understand the sender's and receiver's positions somewhat better.