The phrase "successful schools" refers to educational institutions that are doing well and achieving positive outcomes for their students. Full definition
Not only are we promoting a community and business partnership, we are also emphasizing the characteristics of successful schools in the areas of curriculum, instruction, and assessment. (amle.org)
This will enable teacher and student to have a more successful school year. (theattachmentplace.com)
It works very well as we are one of the most successful schools in the county and are thought of very highly, nationally. (news.bbc.co.uk)