Student to Teacher Ratio
One of the criteria used to compare schools is the student-to-teacher ratio. It is an indication of the staffing resources of the school. The number usually ranges between 10 to 20. So a ratio of 10 means there are 10 students for each teacher at in school.
Generally you would prefer a lower number as it means more teaching resource for each student. If lower teacher-to-student ratio is better, then the conjecture is that a ratio of 1 is the best. It is basically like private tuition. But this is exactly what homeschooling is about. Giving your children the best teaching resource.