A designerly approach to the development of brand extensions: Bridging the divide between behavioural research and design science

This thesis explores the role of design in creating successful brand extensions. Previous research has studied the topic from individual disciplines, focusing on strategies or processes (innovation management) and consumer behaviour (marketing). However, hardly any attention is paid to a very important factor in this context; the design of the brand extension itself. The study accumulates knowledge and approaches from three individual research domains, into an overarching framework. To arrive at this overarching framework, two central research questions were answered:
(1) Which factors that can be influenced by the designer lead to successful brand extensions?
(2) in what ways can the designer be best supported in designing successful brand extensions?
The designerly approach of this thesis has led to the development of two research lines which are interwoven in this thesis: a behavioural line that describes which factors affect the success of brand extensions and a design based support line that describes how designers can influence these factors. The result of this is a set of design support models that includes the Brand Translation Prism and the Triangular Designer Space. The Brand Translation Prism helps designers connect the physical product characteristics, symbolic associations, and overarching core values of a brand, resulting in recognisable brand extensions. The Triangular Designer Space is a model that shows how typicality, novelty, and brand fit jointly influence the success of brand extensions. The two models together form a toolbox for developing successful brand extensions combining a more analytical approach and a more designerly approach. The results of a large empirical study show that respondents use brand-related attributes as antitheses to novelty or as reinforcers to typicality, leading to the new term "brand typicality" as a better predictor of expected market success. The study provides valuable insights into the often-ignored role of design in developing successful brand extensions and offers a practical framework for designers to create successful brand extensions.