Advertising Principles - Evidence-based principles

Predicting the effectiveness of alternative advertisements

A paper by Armstrong, Du, Green, and Graefe tested a new method—the Persuasion Principles Index (PPI)—for predicting the relative effectiveness of advertisements. The PPI is a rating of conformity to evidence-based persuasion principles. The software is freely available on, along with a self-training course that takes about an hour. The software can be used by novices or experts. The rating for a print ad can be completed in less than 30 minutes per rater.

The PPI can also be used to rate video commercials, brochures, and  other types of advertisements.


When using ratings by novices, the PPI correctly predicted which ad in a pair of print advertisements was more effective for 74 percent of the  97 pairs of ads. In contrast, the typical method for picking best ad, expert judgment, was correct for 55 percent of the pairs—a bit better than guessing— and Glossary Link copy testing was correct for 59%.


The paper, "Predictive validity of evidence-based persuasion principles: An application of the index method," is published, along with commentaries, in the European Journal of Marketinghere. Further analysis of the predictive validity of the PPI is here.


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