This brief is part of a broad landscape analysis focused on policy and practice issues related to the recognition of prior learning. The landscape analysis focuses on issues arising in the practice of the recognition of prior learning, policies that encourage or limit its adoption, and key research needs and future directions for the field. This brief summarizes the existing research on two distinct set of exams, College Board's College Level Examination Program (CLEP) and ACT's WorkKeys assessment. While these assessments, CLEP and WorkKeys, measure different skill sets--CLEP is a subject-specific exam of college-level material and WorkKeys is an assessment of foundational work-readiness skills--they both are used in assessing an individual's knowledge and skills and allow the test taker to document the skills and knowledge acquired, which are key components of recognizing learning that may take place outside of the formal classroom setting. In addition to reviewing the existing research on these exams and outcomes of students who participate in credit by examination, this brief offers considerations for future research to better understand the role of credit by examination in supporting student success and ways to promote data-informed decision-making that will better position credit by examination opportunities for students.