Public speaking: is presenting the gains enough to inform a decision?

When addressing a committee, highlighting a project's benefits seems like effective public speaking. The managerial question is more precise: how can a risky decision be presented without the choice of words deciding in place of the arguments?

What the literature establishes

Amos Tversky and Daniel Kahneman (1981, Science) show, in experimental decision problems, that different descriptions of equivalent consequences can alter preferences. In their classic public health problem, describing outcomes as lives saved or deaths leads to different choices between a certain option and a risky one. For speakers, this identifies a risk: a factually accurate formulation can still steer a decision.

The mechanism: outcomes are evaluated against a reference point

Daniel Kahneman and Amos Tversky (1979, Econometrica) propose a model in which outcomes are evaluated as gains or losses relative to a reference point, rather than solely as final states. In this model, sensitivity to losses and the weighting of probabilities help explain choices that depart from expected utility theory. This theoretical framework, from the same research programme, helps explain why 'preserving' a resource and 'avoiding its loss' are not necessarily psychologically interchangeable formulations.

The premature conclusion

The commercial conclusion would be to systematically choose whichever frame encourages agreement. Yet these studies show neither that a positive frame is always more persuasive nor that a preference obtained in this way improves the decision. In a management presentation, making equivalent consequences visible is therefore a transparency precaution, not a proven formula for better judgement. (our executive and employee training programmes)

What the evidence cannot promise

These articles examine choices in experimental problems, not the effectiveness of public speaking training for presentations to professional committees. They do not allow a direct estimate of the size of an effect in a medtech presentation, a higher education governing body or a sports organisation. Expertise, discussion and access to data are important differences between these settings and the tasks studied.

A practical check in Lausanne

In an SHR 'Public Speaking & impact' workshop in Lausanne, a medtech team, a higher education institution, an international sports organisation or a scale-up from the Lake Geneva region can test two versions of the same recommendation using identical data: one expressed as gains, the other as equivalent losses. Randomly assigning participants to the versions, keeping the speaker and duration unchanged, and collecting individual choices before any discussion makes it possible to calculate the percentage-point difference between the proportions supporting each option. Asking for a written explanation also helps examine what participants retained; in a small group, the difference remains a local signal worth investigating, not generalisable proof. To go further: explore the Public Speaking & Impact training in Lausanne, or browse our executive and employee training programmes in Switzerland.

In pictures: Public Speaking & Impact in Lausanne

• public speaking & impact
• Lausanne
• research
• training lausanne