Prior to the publication of McCarthy's text, the concept of a "marketing mix" was being debated, however, there was little consensus among marketers about what elements should comprise the marketing mix. They relied on checklists or lengthy classifications of factors that needed to be considered to understand consumer responses. Neil H. Borden of the Harvard Business School developed a complicated model in the late 1940s, based upon at least twelve different factors. In contrast, McCarthy's concept was a simplifed, memorable set of factors for managerial planning and decision-making.