Library research studies have provided evidence that teacher-librarians (TLs) impact student academic success; nevertheless, TLs statewide and internationally are at a critical juncture due to stakeholder groups' ambiguous perceptions regarding their influence on student achievement. The problem in this study involves a local independent school district's lack of conclusive evidence to demonstrate TLs' contribution to student achievement on standardized testing. The purpose of this study was to examine the perceptions of TLs, classroom teachers (CTs), and administrative staff (AS) concerning student achievement as instructed by local TLs. Using Piaget's cognitive theory and Mezirow's transformative learning theory, this qualitative case study explored the perceptions of 15 participants and acquired clarification regarding the TLs' instructional practice. The interview questions focused on perceptions of 5 CTs, 5 AS, and 5 TLs regarding the instructional role of TLs on students' academic success as well as the evidence provided by these stakeholders regarding the value of school libraries. Data collection with semi-structured interviews followed by an open coding thematic analysis revealed 7 themes: (1) involvement in curriculum, (2) flexibility of schedule, (3) preconceived misconceptions, (4) using an evidence-based practice approach, (5) collaboration, (6) access to materials, and (7) a conducive learning environment. The resulting project consisted of a policy recommendation created for augmenting stakeholder perceptions. The project contributes to social change by fostering an informed societal positive perception of the TLs' instructional influence on student academic achievement and by offering a measurable interpretation of the TLs' educational value to the learning community that may transform stakeholder perception locally and worldwide. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]