Abstract
Purpose. The purpose of this study, using Hord's five dimensions of successful PLCs was to compare high-achieving comprehensive high schools and low-achieving comprehensive high schools PLCs in Riverside and San Bernardino Counties to determine teachers' perceptions of importance and impact on student achievement. Methodology. This mixed-methods study combined quantitative and qualitative data. Descriptive statistics were used to measure teachers' perceptions of the degree of importance and impact of Hord's five dimensions of PLCs on student achievement. Qualitative methods were used to identify themes relating to teachers' perceptions and rankings of the most impactful of Hord's five dimensions on student achievement. Hipp and Huffman's (2010) PLCA-R survey instrument and six embedded open-ended questions were used to examine school practices as they related to Hord's five dimensions of PLCs. Findings. High-achieving high school PLCs perceptions of their school practices reflect the importance and impact of Hord's five dimensions for student achievement. Participants perceptions averaged higher than the low-achieving PLC schools in all five dimensions, especially in shared and supportive leadership which (a) promotes collaboration, (b) decision making, (c) shared responsibility, and (d) accountability. High-achieving and low-achieving high school PLCs participants' perceptions of their school practices averaged lower in shared personal practices and supportive conditions–structure. Respondents' perceived not enough time was scheduled for peers to observe and provide feedback on instructional practices. Overall, the high-achieving high school PLCs school practices reflect a PLC school culture to a higher degree when compared to the low-achieving high school PLCs. Conclusions. The findings revealed there was a significant difference in the perceived degree of importance of Hord's five dimensions of PLCs for student achievement between high-achieving and low-achieving high school PLCs. There was a difference in the degree of impact for student achievement on all the dimensions except collective learning and application and supportive conditions–structures. Recommendations. Further research is needed on the dimensions shared personal practices and supportive conditions-structure in California school districts where PLCs are systemic.