Despite the potential of the Next Generation Science Standards (NGSS) to positively impact science education, educators require time and support to learn the standards and their implications for science teaching and learning in the classroom. The Hawai'i Department of Education adopted the NGSS in 2016. While schools received professional development for the NGSS, little is known about how teachers view the NGSS or are applying the standards in their science teaching practices. In this multiple case study, I investigated how five middle school science teachers in one complex area of Hawai'i were making sense of the NGSS in terms of their beliefs and practice. Using semi-structured interviews, I investigated teachers' views and beliefs about the NGSS. Through the analysis of teachers' lesson descriptions, I examined the presence of the three-dimensional elements of NGSS in participants' lessons. My findings revealed that the five participating teachers attended to the three dimensions more than any of the other conceptual shifts of the NGSS. However, although the three dimensions were present in all participants' lessons, the three dimensions were seldom present at the appropriate middle school grade level. Participants also expressed a range of conceptions about phenomena when describing the phenomenon in the lesson, which suggests participants have some uncertainty about what phenomena are and the role phenomena play in science teaching and learning for the NGSS. Furthermore, participants from the same school tended to espouse similar beliefs about the NGSS. While the findings should be weighed against the limitations of this exploratory multiple case study, the results of the study may provide useful points for discussion to those interested in supporting teachers and schools with implementing the NGSS in science teaching and learning. [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.]