Collegial feedback will provide insight on the beliefs that underlie any actions. But such feedback is unlikely in a school that isn't already committed to continuous improvement and collegial support. To hold high expectations for students, teachers must commit themselves to several actions. Know what students know and don't know. Getting a firm hold on the starting point of each student helps teachers know what is within a student's reach.
Low expectations are often the product of low performance and due to a lack of knowledge or skill.
Establish clear, high expectations for students. Communicate them, model them, and provide samples of work that demonstrates those expectations. Give students multiple opportunities to meet the expectations. Schools with no-failure policies clearly communicate that failure is not an option. Shift grading and assessment practices to identify what a student does well rather than what a student does incorrectly.