An effective teacher should: have excellent knowledge of curricula and assessment practices; have strong subject knowledge; know how to present concepts meaningfully; set clear objectives and high expectations; be innovative; plan inspiring lessons; manage time efficiently; use resources creatively; differentiate instruction to meet varying needs and styles; stimulate interest and thinking. To address mixed-ability classrooms, teachers should: have knowledge of each student's needs; differentiate instruction and contexts; create individualized teaching and assessment; set appropriate expectations; plan based on competencies; update practices; create a positive environment; reinforce concepts; ensure clear aims; vary questioning; focus questions; make effective use of resources; organize classroom; ensure tasks challenge all students. The determining factor