Search	Terms	Hits
1	Class Size* OR “Classroom Environment” OR “Crowding” OR “Flexible Scheduling” OR “Small Classes” OR “Teacher Student Ratio”	11.669
2	Class Size* OR “Classroom Environment” OR “Crowding” OR “Flexible Scheduling” OR “Small Classes” OR “Teacher Student Ratio” AND Primary School* OR Elementary school* OR secondary school* OR middle school* OR Junior high OR “Middle Schools”	228
3	((“Class Size*” OR “Classroom Environment” OR “Crowding” OR “Flexible Scheduling” OR “Small Classes” OR “Teacher Student Ratio”) AND (Primary School* OR Elementary school* OR secondary school* OR middle school* OR Junior high OR “Middle Schools”) AND (learn* OR develop* OR perform* OR achiev* OR abilit* OR outcome* OR improve*))	188