Purpose: This study sought to identify, understand, and describe the decision-making processes used by school districts to determine the middle school science course sequence as part of the adoption of the Next Generation Science Standards. Additionally, this study explored and described the expressed comments, feelings, and beliefs of participants involved in the decision process about their experience in the decision-making process and the outcome. Methodology: This multiple case study focused on four cases--three school districts that chose the integrated approach and one district that chose the discipline approach. Ten participants represented the four school districts. Data were collected from each participant utilizing personal face-to-face interviews. Findings: Significant findings included: Administrators tended to defer to teachers, because of their expertise, to promote consensus and teacher buy-in; prolonged discussions led to expressions of demoralization among teachers; each of the four school districts used a different approach to the decision--one depended on expertise of a dedicated science education leader to make a command decision, while three districts included a broad set of participants to promote consensus; conceptual structuring devices facilitated decision making; science teachers with discipline-specific backgrounds tended to prefer the discipline model and were more reluctant to adopt the integrated approach; the professional identity of the science teacher influenced their preference and their feelings about the outcome; and each participant expressed unique perceptions of who was involved in the decision--teachers tended to downplay the importance of their own influence and to describe the ultimate decision as being in the hands of administrators. Conclusions: There is no best approach to selecting a middle school science course sequence. Multiple decision-making approaches resulted in acceptable outcomes, but any approach can be improved by taking steps to promote levels of trust among constituents. Recommendations: Educational leaders must understand how the "professional identity" and "science content expertise" of science teachers influence their preferences of curricular sequencing. Leaders interested in developing consensus should take careful steps to promote transparency and trust. Participants in the decision should be provided professional development to limit ambiguity, provide guidelines, and promote structuring devices to facilitate the decision. [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://www.proquest.com.bibliotheek.ehb.be/en-US/products/dissertations/individuals.shtml.]