Barnlund's model is an influential transactional model of communication. It was first published by Dean Barnlund in 1970. It is formulated as an attempt to overcome the limitations of earlier models of communication. In this regard, it rejects the idea that communication consists in the transmission of ideas from a sender to a receiver. Instead, it identifies communication with the production of meaning in response to internal and external cues. Barnlund holds that the world and its objects are meaningless in themselves: their meaning depends on people who create meaning and assign it to them. The aim of this process is to reduce uncertainty and arrive at a shared understanding. Meaning is in constant flux since the interpretation habits of people keep changing. Barnlund's model is based on a set of fundamental assumptions holding that communication is dynamic, continuous, circular, irreversible, complex, and unrepeatable.
Cues are of central importance in Barnlund's model. A cue is anything to which one may attribute meaning or which can trigger a response. Barnlund distinguishes between public, private, and behavioral cues. Public cues are available to anyone present in the communicative situation, like a piece of furniture or the smell of antiseptic in a room. Private cues are only accessible to one person, like sounds heard through earphones or a pain in one's chest. Behavioral cues are under the direct control of the communicators, in contrast to public and private cues. They include verbal behavioral cues, like making a remark about the weather, and non-verbal behavioral cues, such as pointing toward an object. Barnlund's model uses arrows going from the communicators to the different types of cues. They represent how each person only gives attention to certain cues by decoding them while they encode and produce behavioral cues in response. Barnlund developed both an intrapersonal and an interpersonal model. The intrapersonal model shows the simpler case where only one person is involved in these processes of decoding and encoding. For the interpersonal model, two people participate. They react not just to public and private cues but also to the behavioral cues the other person produces.
Barnlund's model has been influential as the first major transactional model of communication. This pertains both to its criticism of earlier models and to how it impacted the development of later models. It has been criticized based on the claim that it is not effective for all forms of communication and that it fails to explain how meaning is created.