There are many reasons to implement a thoughtful assessment of student learning in library instruction sessions.
Some reasons for implementing outcome assessment may be external to the library. For example, some accrediting bodies require libraries to provide data about student learning in information literacy sessions. Administrators too may want justification for the programs that libraries offer and libraries may want to communicate to administrators about the value of information literacy programs to students. It is often no longer acceptable to simply state, “the library offered 8 information literacy sessions”, instead libraries are increasingly asked to prove why it is that they offered those 8 information literacy sessions.
Other reasons for implementing outcomes assessment are internal to the library. Understanding what students are learning in information literacy instruction sessions provides a comprehensive look into program offerings and helps libraries evolve and make changes in ways that best support student learning and contribute to the relevancy of the library.
As the world evolves quickly, it is well-advised that all academic libraries begin considering, if they have not already, how they can begin to understand the impact of their programming on student learning.
This chapter in Instruction in Libraries and Information Centers by Laura Saunders and Melissa A. Wong is an excellent reference.
This guide from the University of Texas and this guide from Utah State University are also excellent resources.
ALA also provides a good overview of assessment of information literacy skills.
PALNI provides an Information Literacy Assessment Toolkit that covers assessment for program, course, and class levels as well as a list of tools that could be used as part of assessment work.
Snapshots of Reality: A practical guide to Formative Assessment in Library Instruction by Mary Snyder Broussard, Rachel Hickoff-Cresko, and Jessica Urick Oberlin is another good resource.