Communication Theory: Key Concepts

Communication is the production and exchange of information by use of signs and symbols. The processes involved include encoding, transmission, reception, decoding, and interpretation of information. The key question the communication theory addresses is: Who says what to whom, through what channel, with what effect? This simple frame work was suggested by Harold Lasswell in 1939. In current view of communication theory, effects are defined by how audiences process the messages. Prior beliefs and social backgrounds affect how people interpret and respond to messages. Thus, in attempting to develop effective health communication interventions, one must consider the sender, the message, the channels, and the intended audience.

Figure 11-1 shows the communication process (Edberg, 2007).

The sender

The sender of health communication messages may be someone who is a public figure (e.g., the President or First Lady, the Surgeon General, or the governor), someone who is an influential role model (e.g., Tiger Woods, Michael J. Fox), or someone who is friendly and wise, such as a animated character (Weinreich, 1999). The sender that delivers health messages can have an important impact on whether messages are perceived as credible. The most influential sources of communication may vary with the specific health behavior change and with the characteristics of the intended audience: therefore formative research is necessary to identify the most appropriate sender for specific groups.

For example, previous research revealed that health providers are often identified as a credible sender of health messages relevant to health behavior change (Snell and Buck, 1996). Promotion of health behaviors that are mediated by social norms may be communicated more effectively through peer groups, family, or religious leaders (Cruz and Mickalide, 2000).

The Message

A message is a statement that usually contains only one main idea and relates to the communication objectives specified by the health communication intervention (Ferguson, 1999). The message content is usually derived from behavior change and communication theories as well as data collected through research. The most effective messages are those designed to change one or more well-defined behaviors.

The Channels

The channels through which health communication messages are disseminated include the mass media (television, radio, magazines, newspapers, and billboards); direct mail, brochures, posters; interpersonal communications (in-person and telephone counseling); music, computer games, and DVD; and the internet. Different age, gender, racial/ethnic, and socioeconomic groups tend to favor different media, so it is important to investigate which media are best for each group. For example, a health communication campaign may use billboards and store displays to reach disadvantaged inner-city dwellers, and newspapers or newsletters to reach suburban households.

The Audience

To develop effective health communication interventions, you need to have a clear definition of the audience you are trying to target. The intended audience is the segment of the population whose behavior a health communication intervention attempts to change. For example, the intended audience for a mammography campaign for older women will include women varying in race/ethnicity, income, education, job history, age, and family history.

Other factors affecting the communication process include:

• Context of the communication (e.g., formal, informal)
• Relationship between sender and receiver (e.g., Does the sender have power over the receiver?)
• The meaning attached to the channel (e.g., Wall Street Journal vs. gossip)

In sum, the use of media and communications in public health aims to provide information and impact the agenda of what people are concerned about, in order to set the stage for action.