This study demonstrates how a team of librarians sustained authentic assessment across multiple studies in order to inform changes to an information literacy curriculum. It demonstrates the cyclical and action-based nature of assessment, including closing one loop only to reopen another and begin the assessment process again, emphasizing the importance of sustainability and making changes that increase student learning. Researchers analyzed 79 English composition papers for evidence of information literacy skills, expanding upon a previous study which established information literacy skill benchmarks. Findings from the previous study led to the development of new library instruction lessons, which targeted skills students struggled with – mainly topic refinement and information synthesis. To measure the impact of the modifications, the authors used two rubrics as well as a citation analysis to identify shifts in student learning. Findings indicate that the new lessons contribute to student improvements in synthesis, topic refinement, and source variety. This study illustrates the importance of engaging in an ongoing cycle of assessment and continually making improvements to instruction practices while implementing evidence-based decisions.