AU - السميري، خلود عبدالرحمن مسلم AU - أبو دف، محمود خليل AU - المزين، سليمان حسين موسى AU - خلف الله، محمود إبراهيم AB - The study aimed to identify teamwork efficiency among secondary school principals in Gaza governorates, and to verify the nature of its relationship with the quality of professional performance of their teachers. The study population consisted of all secondary school principals, whose number, according to official statistics for the academic year 2019/2020, was (148) male and female principals, and the number of teachers reached (4,719) male and female teachers. The researcher chose the comprehensive survey method for choosing the school principals, numbering (148) principals, and selected a random stratified sample of (400) teachers, who constituted (8.5%) of the total teachers’ populations. The researcher used a questionnaire to measure the efficiency of teamwork among principals, as it consisted of four areas (participation in decision-making, communication, motivation, and conflict management). A questionnaire was used to measure the quality of teachers’ professional performance, and it consisted of two areas (professional skills, occupational trends and values). The researcher used the descriptive analytical approach. The study reached many results, the most prominent of which are the following: 1) The level of teamwork efficiency among secondary school principals in the governorates of Gaza, from the teachers’ viewpoint, reached a medium degree, with a relative weight (64.20%). 2) There are statistically significant differences at the level of significance (α≤0.05) between the averages of the study sample’s estimates of the level of teamwork efficiency among secondary school principals in the Gaza governorates, due to the gender variable in favour of female principals, while there are no statistically significant differences at the level of significance (α≤0.05) attributable to the academic qualification variable. 3) There are statistically significant differences at the level of significance (α≤0.05) between the averages of the study sample’s estimates of the level of efficiency of teamwork among secondary school principals in Gaza governorates, due to the variable of years of service in favour of (less than 5 years / more than 10 years). 4) The quality of the professional performance of teachers in secondary schools in the Gaza governorates from the point of view of their principals came to a large degree, with a relative weight (68.20%). 5) The presence of a relationship at the level of statistical significance (α≤0.05) between the averages of the responses of the study sample in their estimates of the level of efficiency of teamwork among school principals and the quality of teachers’ professional performance. The main recommendations of the study are as follows: 1) The need to train principals on the practical way to manage teamwork in schools. 2) The necessity of educating teachers about the importance of their multiple roles as members of work teams and their impact on developing teachers’ skills and abilities in their various specializations. (Author’s abstract) http://search.shamaa.org/abstract_en.gif OP - أ-ز، 134 ص. T1 - كفاءة العمل الفريقي لدى مديري المدارس الثانوية في محافظات غزة وعلاقتها بجودة الأداء المهني لمعلميهم [رسالة / أطروحة] UL - https://library.iugaza.edu.ps/thesis/129408.pdf النص الكامل (PDF) 1 http://search.shamaa.org/fulltext.gif