Overview

The Two-Step Flow theory was developed by Paul Lazarfeld, Bernard Berelson, and Hanzel Gaudet and was published in their book The People’s Choice (1944). Originally intended for political campaign applications, it can be a useful tool in developing and disseminating information in the health education field. The basis of the Two-Step Flow is that personal, informal contact with the target audience is more likely to incite the desired behavioral change than if the individual receives the information any type of formal or non-personal contact (commercial, magazine ad, spokesperson etc.) (Katz, 1973).
 

Two-Step Flow Model

Stage One

• The message is received by individuals who pay attention to mass media (Katz, 1973).

Stage Two

• Then these individuals (dubbed opinion leaders) relay the message, along with their take on the message, to people they are in contact with (Katz, 1973).
• The individuals who receive the message in the second stage are more likely exhibit change in accordance to the message due of the trust they have in the source (Katz, 1973).

In application, the Two-Step Flow is a valuable tool for defining an audience and then adjusting the tone and format of the messages to suit that audience. The theory however will not (should not) completely construct the messages. Other behavioral theories, such as any of the Health Behavior Models, should be used in conjunction with the Two-Step Flow Theory to create effective messages.
 

Example

The Two-Step Flow is useful when leaders of a target audience exist and can be isolated. For example, in applying the theory on a campaign that concerns a condition that is prevalent in young boys (ages 5-7), one might target the scoutmasters of boy scout troops. The scoutmasters would act as a way to relay messages to parents and their children. If the parents are told by the scoutmaster to have their children checked for the condition, according to the theory they are more likely to do it than if they receive the information from a public source such as a magazine or commercial. This scenario holds true to the Two-Step Theory because the message is relayed in an informal way through an opinion leader to a second stage audience.
 

Citations

Katz, Elihu (1973). The two-step flow of communication: an up-to-date report of an hypothesis. In Enis and Cox(eds.), Marketing Classics, p175-193. http://poq.oxfordjournals.org/content/21/1/61.short

Figure from:
http://www.utwente.nl/cw/theorieenoverzicht/theory%20clusters/mass%20media/two_step_flow_theory-1.doc/