The RSS West Midlands invited Steve Ferris to speak at their local meeting at the Department of Statistics, University of Warwick, on May 7, 2015. Steve gained his first degree in Statistics at Coventry University and completed his PhD at Edinburgh. He is now a statistical consultant at mmr research UK, a company performing market research for a number of big names in the food and drink industry. The presentation he gave was very much focused on his current work on product optimisation.
Steve introduced the audience to the idea of product testing and the challenges involved with 'delivering the maximum delight to the maximum number of people'. He stressed the fact that a huge quantity of newly introduced products in the food and drink sector remain less than six months on supermarket shelves due to poor sales performance. For companies, it is thus key to research acceptability by consumers before entering the market.
The type of data Steve analyses comes from two categories: sensory data and consumer data. While the former reports on certain aspects of a given product, such as flavour, texture and appearance, the latter quantifies a degree of 'liking' by a consumer. The challenges in this area lie mainly on the practical rather than on the statistical side. In order to guarantee the quality of data, mmr performs eight to twelve weeks of sensory evaluation with the help of a trained panel. This panel blindly grades each product on a scale of 0-100 points with respect of typically fifty or more different sensory characteristics, thus delivering the key sensory data. Consumer data is collected via carefully designed questionnaires, keeping in mind that questions such as 'would you be willing to buy this product?' are actually implied by simply enquiring 'do you like it?'.
Steve presented an internal study about shortbread in order to illustrate the statistical models involved in his research. His typical approach is based on a complete design, where every tester in the panel tries every product. This allows for segmentation and enables mmr to elicit which aspects of a product are linked to a certain degree of liking, while differentiating results into groups of people with different preferences. Some of the challenges he comes across are the position effect and carryover effect: the order in which products are tested has a marked impact on the perception by a consumer.
To conclude, Steve told some interesting stories about how brand loyalty influences consumer's choices and how market research in the food and drink sector might lead to a variant of a given product being introduced rather than a change of the original one.