Predictive validity of evidence-based persuasion principles: An application of the index method
Abstract
Purpose
This paper aims to test whether a structured application of persuasion principles might help improve advertising decisions. Evidence-based principles are currently used to improve decisions in other complex situations, such as those faced in engineering and medicine.
Design/methodology/approach
Scores were calculated from the ratings of 17 self-trained novices who rated 96 matched pairs of print advertisements for adherence to evidence-based persuasion principles. Predictions from traditional methods – 10,809 unaided judgments from novices and 2,764 judgments from people with some expertise in advertising and 288 copy-testing predictions – provided benchmarks.
Findings
A higher adherence-to-principles-score correctly predicted the more effective advertisement for 75 per cent of the pairs. Copy testing was correct for 59 per cent, and expert judgment was correct for 55 per cent. Guessing would provide 50 per cent accurate predictions. Combining judgmental predictions led to substantial improvements in accuracy.
Research limitations/implications
Advertisements for high-involvement utilitarian products were tested on the assumption that persuasion principles would be more effective for such products. The measure of effectiveness that was available –day-after-recall – is a proxy for persuasion or behavioral measures.
Practical/implications
Pretesting advertisements by assessing adherence to evidence-based persuasion principles in a structured way helps in deciding which advertisements would be best to run. That procedure also identifies how to make an advertisement more effective.
Originality/value
This is the first study in marketing, and in advertising specifically, to test the predictive validity of evidence-based principles. In addition, the study provides the first test of the predictive validity of the index method for a marketing problem.
Keywords
Acknowledgements
Kay A. Armstrong, Heiner Evanschitzky, Rachel Kennedy, Nick Lee, Shengdong Lin, Leonard Lodish, Jörg Matthes, Sandeep Patnaik, Barbara Phillips, Rik Pieters, Denise Rousseau, Martin Schreier, Byron Sharp, Dave Walker, Malcolm Wright, and Guohua Wu, along with two anonymous reviewers, provided peer review that led to substantial improvements. Alexandra House helped to develop the software used in this study and was also involved in collecting data and rating advertisements. We received advice on the design of the copy testing procedures from Dave Walker, Sandeep Patnaik, and Don Esslemont. We thank the Alex Panos Fund and the Ehrenberg-Bass Institute for partial financial support for this project. Useful suggestions were received when earlier versions of this paper were presented at the 2011 International Symposium on Forecasting in Prague, the Center for Advanced Studies at LMU Munich in September 2013, the Business School at Vienna University in September 2013, the 2014 Annual Conference of the International Communication Association, and the 2014 International Symposium on Forecasting in Rotterdam. Laura Blagrave, Hester Green, Emma Hong, Jennifer Kwok, Esther Park, and Lynn Selhat edited the paper. We take responsibility for any remaining errors.
Citation
Armstrong, J.S., Du, R., Green, K.C. and Graefe, A. (2016), "Predictive validity of evidence-based persuasion principles: An application of the index method", European Journal of Marketing, Vol. 50 No. 1/2, pp. 276-293. https://doi.org/10.1108/EJM-10-2015-0728
Publisher
:Emerald Group Publishing Limited
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