Core message: meaning and application

A campaign can contain ten good sentences and still leave little behind. Ask someone a week later what stuck, and you hear a stray detail or nothing. A core message sets out in advance the one idea a target group should be able to retell after contact.

A core message is the one main idea that a target group should remember after contact with your communication and be able to retell in their own words.

It sits between the proposition (what you offer and why it has value) and the execution (slogan, copy, visuals and tone). Supporting messages make it concrete. A core message is a choice and a hypothesis: whether the target group actually remembers and understands it only becomes clear through testing per target group.

Core message is a practical term from communication and advertising, not a scientific construct with one original publication. Advertising briefs use a related term, the single-minded proposition: the one promise a creative team focuses on. The scientific sources consulted show no fixed origin for either term; this article therefore names no originator.

Neurofactor uses this working definition: the core message is the one main idea that a defined target group, in a specific decision context, should remember after contact. It is phrased from the receiver's perspective, not the sender's, and applies per target group. This is an editorial convention, not a validated model.

The difference from related concepts lies in the question each one answers.

A slogan can express the core message, or simply carry the brand. The proposition describes what the offer delivers; the core message selects what a group should remember from it. For a product's promise, read What is a product promise?; for tone, read What is tone of voice in a target group profile?

Supporting messages answer the follow-up questions: how does it work, what does it deliver, and why should I believe it? They make the core message concrete without replacing it.

Context determines how much of this structure remains: a poster often has room only for the core, while a web page adds supporting messages and evidence. Two checks help (editorial advice):

• Core only. A piece with only the core message must still be accurate and understandable.
• Supporting messages only. From a piece with only supporting messages, the reader should be able to infer the core message.

The idea of one main idea fits with memory research. In a review article, Cowan concludes that people can briefly hold about three to five meaningful units (chunks) at once, fewer than the often-cited seven (Cowan, 2001). That research concerns experimental memory tasks, not campaigns, and does not show that one message is remembered better than two. It does make it plausible that many equally weighted points compete for limited capacity.

Simplicity also affects how people judge information. In a review, Alter and Oppenheimer discuss research in which the ease of processing information, for instance through simpler language, influences judgements, including judgements of truth (Alter & Oppenheimer, 2009). Processing ease colours judgements, but it does not guarantee that a simple sentence will be remembered or believed.

Petty and Cacioppo's elaboration likelihood model (ELM) describes two routes to attitude change (Petty & Cacioppo, 1986). On the central route, a person carefully weighs the substantive arguments. On the peripheral route, an attitude changes because the topic becomes associated with positive or negative cues (Petty et al., 1983).

In an advertising experiment, argument quality carried more weight under high involvement, and a well-known athlete as endorser carried more weight under low involvement (Petty et al., 1983). The authors state as a premise of the model that attitudes formed via the central route are more enduring and better predict behaviour.

For a core message, this implies (interpretation): it needs an argument that holds up under scrutiny and must be recognisable at a glance.

Choosing a core message also means choosing what you do not emphasise. Entman describes framing as selecting some aspects of a perceived reality and making them more salient in a text, so as to promote a particular problem definition, causal interpretation, moral evaluation or treatment recommendation (Entman, 1993). In his view, salience increases the likelihood that receivers notice, process and remember information, but salience arises in interaction with what the receiver already thinks.

Framing is a topic in its own right. For the core message, one lesson suffices: the main idea sets the frame for everything else. Choose convenience, and people read your evidence as evidence of convenience.

In 1968, Zajonc proposed that repeated exposure to a stimulus can suffice to make attitudes towards it more positive. He supported this with experiments using unfamiliar words, Chinese-like characters and photographs of faces (Zajonc, 1968). This is known as the mere exposure effect. Three nuances:

• Not a straight line. A meta-analysis of 81 studies found an inverted U-shape: liking first rises with repetition and then declines again. That pattern held under specific conditions, such as visual stimuli (Montoya et al., 2017).
• Different stimuli. The classic studies mainly used unfamiliar, meaningless stimuli, not campaign sentences with content.
• Repetition makes statements more credible. A meta-analysis of 51 studies shows that repeated statements are judged as more true, the so-called truth effect (Dechêne et al., 2010). This concerns the judgement, not whether the statement is correct. So only repeat what you can substantiate.

Consistency (editorial advice): keep the core message stable across channels and over time, and vary the execution, examples and supporting messages. Whether this improves recall in your target group is a testable question.

One offer can solve something different for different groups; what one group sees as a benefit, another takes for granted. Involvement differs too: a group already searching processes arguments differently from one that has never considered the topic.

More core messages are not automatically better: each one requires its own pieces, testing and maintenance, and raises the risk of contradiction. So work (editorial advice) with a shared core that applies to everyone. Choose a separate core message only if research shows that groups really need to remember something different.

1. Define target group and decision context. Which decision or action does the group face?
2. Name what the group thinks now. Use researched insights, such as pain points and objections.
3. Formulate the desired idea after contact. Write one plain sentence from the receiver's perspective, without campaign language.
4. Check the sentence against the proposition. Can the offer deliver this idea? If not, adjust the sentence or the offer.
5. Choose supporting messages and evidence. Which follow-up questions should a piece answer?
6. Check simplicity and frame. Can someone retell the sentence, and which frame does it evoke?
7. Record it as a hypothesis. Note the source, the assumption and how you will test it.

The sentence itself does not tell you whether a core message works. You test it with people from the target group, using criteria set in advance. A simple format (editorial advice): show a piece and ask what someone remembers, in their own words. Compare that answer with the intended core message.

Test each group separately: an average can hide that one group remembers something quite different. How to turn target group insights into variants and choose outcome measures in advance is covered in From target group insights to testable messages.

This example is fictional. The core messages are working hypotheses, not research findings.

Situation. A municipality introduces an app for reporting litter, full containers and dumped bulky waste. At present, residents report by phone, through a web form or not at all.

Decision question. Which idea should each group remember so that more reports arrive via the app?

Available information. Questions received by the customer contact centre and exploratory conversations with residents.

Suitable approach. The team formulates a shared core ('A report via the app goes straight to the right place') and a core message per group.

Possible interpretation. Each group appears to face a different barrier: personal contact, feedback or effort. Whether the core messages address these barriers is unknown.

Next step. The team tests per group, with criteria set in advance, what people retell after a piece, and checks whether the app delivers the promised feedback.

• Treating the slogan as the core message. A slogan can be catchy without clarifying what to remember.
• Making everything important. A core message with three ideas is three core messages.
• Phrasing from the sender's perspective. 'We are innovative' says what the organisation wants to project, not what the target group gains.
• Stretching the research. Studies on memory, processing ease and repetition concerned specific tasks and stimuli and do not predict how one reader responds to your sentence.

A core message is the one idea a target group should remember after contact. Research on memory, processing, framing and repetition helps you formulate it carefully, but does not prove that it works. Treat each core message as a hypothesis and test what people actually retell.