"Class size" arguments miss the point.

There is talk in the legislature of spending hundreds of millions of dollars to reduce "class size".  The money would be spend building more classrooms and hiring more teachers.

A "class" in the usual sense means a group of students who are formed into "thought choirs"  of various sizes, that will think and learn together for a year at a time.  They usually find themselves seated in a formation of columns and rows suggesting headstones, and hence the name, cemetery seating.

The students in most classes have only one commonality, their age, the year of their birth.  This qualifies them to join the group, there to learn exactly the same things, at exactly the same speed, for a year.

By definition the model moves too slowly for better students and too fast for poor students.  What are they being prepared for?  Where again in their lives will students be expected to perform in formation?  Even if it were possible to herd kittens so to speak, why would we want to? 

Forming students into classes benefits no one in those classes; not teachers and not students.  It is a management tool, useful to administrators and legislators.  Their need to gather, compile and interpret performance statistics about education is perverting the actual delivery of education.  Classes do not serve class members.  What seems like an efficiency is really a hindrance.

The ultimate goal of education is to produce independent learners.  It should be the primary objective.  Were it, teachers would then find themselves in charge of  classes of largely independent learners, each progressing at their own best pace.  All else equal, a teacher can "teach" many more independent learners than they can group learners.  At that point, class size becomes considerably less relevant.  As long as the teacher still has time to give every student individual attention they need, the class is not too large.

When independent learning becomes the norm, teachers are freed up to give individual attention to students who actually need it, and their performance will increase as well.  We just have to get past the idea that students must learn in unison.

The only time students really need to be somewhere at once, is graduation day.  In order for a high school diploma to be of use to schools and employers, the diploma must certify that certain basic skills have been mastered.

The proponents of lowering class sizes can cite evidence that lowering class sizes promotes learning (as measured by standardized tests).  Citing that evidence ignores the flawed premise; that we must have "classes" in the first place.

Much better we spend a few hundred million dollars bettering education than broadening it.