Educators need to reflect critically on their instruction to continue to be effective. This paper will employ case studies to demonstrate how librarians can improve their teaching by applying critical reflection and action research to their information literacy (IL) sessions. The four lenses model of Stephen Brookfield, an adult education expert, will be used for critical reflection, and how librarians can apply each of the lenses to their teaching will be described. Furthermore, lessons learned from incorporating multiple assessment tools in the same class will be presented because these tools are needed to engage in critical reflection and action research.