This case describes the use of a mixed-methods design for the collection of data to assess the effectiveness of an in-school social marketing campaign promoting a sexual health text message service. A sequential explanatory mixed-methods design was used, with data obtained in a quantitative in-school survey informing qualitative research that included focus groups and in-depth interviews. The use of a mixed-methods approach allowed for information to be gleaned on not only awareness and use of the service but also potential barriers to use that prohibited some adolescents from using the service although they were aware and thought it could be useful. Challenges to the project and lessons learned are discussed
