When manufacturing widgets, making them more exactly alike is often a key to better quality, better speed and less waste. We are definitely NOT interested in this country in making all our students more and more alike. However, achieving a more nearly perfect education for each and every one of them is our goal. An irrelevant or forgotten education costs the student and is an indication of some failure of the educational system to find the right combination for that student. Doing more nearly perfectly with all students is the sort of variance reduction education can aim at.
High quality is cheaper than low quality.
Look to students themselves for ways to improve Lessen fear among teachers, administrators, students and everyone in the system. Give their ideas respect and a trial. Track performance over time. Get an idea of the normal range of performance since it is never actually constant. Performance varies up and down without important cause.