This study analyzes a sample of students' writing to assess their understanding of marketing concepts in the context of a Principles of Marketing course. Content analysis of pre- and post-essays was used to assess student knowledge of marketing concepts. The data was collected in Principles of Marketing classes. and highlight that many students bring an advertising and sales bias into the Principles of Marketing classroom and leave with stronger ideas of relationship and value. The infrequency with which both distribution and pricing are discussed in the essays highlights the need for additional emphasis in these areas. The methodology could be applied in a variety of marketing courses and range of applications for the purpose of course- or program-wide assurance of learning.