ERIC Identifier: ED259454
Publication Date: 1984-00-00
Author: Ellis, Thomas I.
Source: ERIC Clearinghouse on
Educational Management Eugene OR.
Class Size. ERIC Clearinghouse on Educational Management: ERIC
Digest, Number Eleven.
How large should classes be? Research indicates that the relationship between
class size and instructional effectiveness depends on many related variables,
such as age level of students, subject matter taught, and instructional methods
used. Recent statistical syntheses of this research reveal that the
instructional benefits of smaller classes are most significant for classes
numbering under 20 students; in those with 25 to 40 students class size has
little overall effect on educational quality.
WHY IS CLASS SIZE A CONTROVERSIAL POLICY ISSUE?
Class size is a policy issue that has perennially divided teachers and
policymakers, especially during contract negotiations. Common sense tells us, as
teachers argue, that smaller classes facilitate increased student-teacher
interaction, allow for thorough student evaluation, and provide (potentially)
far greater flexibility in teaching strategies.
Smaller classes also reduce teachers' workload per class and, therefore,
permit teachers to allocate more time to class preparation and less to grading
papers or tests. Finally, smaller classes tend to minimize student discipline
problems because teachers can more easily keep all students under their watchful
eye, allowing more time for instruction and reducing the emotional strain of
Common sense also tells us, however, that smaller classes are considerably
more expensive for a school district to maintain because they require a lower
student-teacher ratio (hence an expanded teaching staff) and more classroom
space per student population (hence expanded or remodeled facilities).
Are the benefits of smaller classes worth the cost? This question has
generated acrimonious debate between organizations representing teachers and
administrators respectively, but the issues involved in the debate are too
complex and various to yield a simple judgment for or against reducing class
IS CLASS SIZE RELATED TO STUDENT ACHIEVEMENT?
Until recently, research offered little help in resolving the class size
controversy. In his 1978 review of research on the topic, Thompson maintained
that research findings were necessarily inconclusive because of the intrinsic
relativity in the definition of "small" or "large," the inherent imprecision of
outcome measures, the subjectivity of process measures, and the plethora of
uncontrolled variables in even the best research designs (1978). Thompson
concluded that the relationship of class size to educational effectiveness
involves too many complex issues to be reduced to a single testable hypothesis.
From 1978 to 1980, however, three controversial "meta-analyses" of class size
research were published by Glass and Smith; these analyses have since come to
dominate discussion of the issue. Smith and Glass employed sophisticated
statistical methods to correlate the findings of 80 studies that yielded over
700 comparisons of smaller and larger classes with respect to student
achievement, classroom processes, and teacher and student attitudes. Their
conclusion is unequivocal: a positive correlation can be drawn between smaller
classes and all these variables.
Smith and Glass came under attack almost immediately by the Educational
Research Services, which published an extensive critique of their methods and
findings. ERS's principal objections were that statistical "meta-analysis"
precludes identification of meaningful clues contained in the research, that
conclusions are overgeneralized from a few "well designed" studies that received
disproportionate emphasis, and that the findings as a whole do not justify
general class size reductions.
The latter objection is based on graphs from the Smith and Glass studies
themselves, showing that improvement in student achievement and other
educational variables does not become dramatic or significant until class size
is reduced below 20 pupils. Such a goal is simply not financially feasible in
most school districts without drastic remodeling of facilities and expansion of
Since ERS published its critique, others have arrayed themselves for or
against Smith and Glass, whose studies have become a point of reference in
nearly everything written on the subject.
IN WHAT SETTINGS ARE SMALLER CLASSES MOST BENEFICIAL?
In general, research findings show that smaller classes are likely to be most
beneficial for younger (elementary school) students, economically or
educationally disadvantaged students, and exceptional students at both ends of
the scale--gifted and disabled.
Research has shown that smaller classes are most beneficial in reading and
mathematics at the elementary level, while at the secondary level class size
tends to make little difference for student achievement in most subject areas.
The areas where smaller classes are most likely to be advantageous at the
secondary level are those that emphasize acquisition of skills rather than
mastery of content--areas such as industrial arts, fine arts, music, and
A number of studies, such as one by Shapson and colleagues, have demonstrated
that teachers do not necessarily modify their teaching strategies when placed in
smaller classes. Shapson found that class size makes a large difference to
teachers in terms of their attitudes and expectations, but little or no
difference to students or to instructional methods used. He concluded that
teachers need to be trained in instructional strategies for various size
WHAT ARE LESS EXPENSIVE ALTERNATIVES TO AN ACROSS-THE-BOARD REDUCTION IN
As Berger has observed, the large volume of class size research has yielded
few empirically verifiable generalizations to guide formulation and
implementation of educational policy. Even if the Smith and Glass analyses are
valid, significant reductions in class size are fiscally impossible in most
school districts, while small reductions within the 25-40 student range do not
produce sufficient achievement gains to make them worth the cost.
The focus on numbers tends to obscure a more basic question that includes but
goes beyond class size: Assuming a limited amount of resources, how can
instructional arrangements be best adapted to the particular needs of each
class? Berger lists four general strategies available to administrators for
modifying instructional arrangements:
--modify distribution of instructional staff
--modify instructional methods
--modify distribution of students
--modify exacerbating factors
Because of the multiple variables involved, class size decisions are best
made at the building level on a case-by-case basis, with teachers participating
in the decision-making process, rather than at the district level as a blanket
policy. Intelligent decisions about class size also presuppose the discretion to
permit small classes in contexts where they are most beneficial, as noted in the
Furthermore, administrators may choose among numerous less expensive
alternatives to smaller classes. These include teacher aides (who can be useful
in a variety of disciplines such as math, science, and language arts), parent
and community volunteers, a staggered schedule, special laboratories or centers,
team-teaching, extended day programs, cooperative learning, and computers or
other individualized instructional aids.
Finally, it is important to recognize that agitation by teacher unions for
smaller classes is frequently a manifestation of teachers' concern, not for the
number of students in one class, but rather for their overall workload--the
total number of students an instructor faces. Therefore, any measures that can
reduce teacher's workload or provide methods for alleviating the burden of that
workload are negotiable substitutes for an overall reduction in class size.
FOR MORE INFORMATION
Berger, Michael A. "Class Size Is Not the Issue." Paper presented at the
annual meeting of the National School Boards Association (Atlanta, GA, April
17-20, 1982). ED 231 061.
Cacha, Frances B. "The Class Size and Achievement Controversy." CONTEMPORARY
EDUCATION 54 (Fall 1982): 13-17.
Educational Research Service. CLASS SIZE RESEARCH: A CRITIQUE OF RECENT
META-ANALYSES. ERS SPECIAL REPORT. Arlington, VA: Educational Research Service,
1980. ED 187 032.
Filby, Nikola, and others. WHAT HAPPENS IN SMALLER CLASSES? A SUMMARY REPORT
OF A FIELD STUDY. Class Size and Instruction Project. San Francisco, CA: Far
West Laboratory for Educational Research and Development, 1980. ED 219 365.
Glass, Gene V., and Mary Lee Smith. "Meta-Analysis of Research on Class Size
and Achievement." EDUCATIONAL EVALUATION AND POLICY ANALYSIS 1 (January-February
Hedges, Larry V., and William Stock. "The Effects of Class Size: An
Examination of Rival Hypotheses." AMERICAN EDUCATIONAL RESEARCH JOURNAL 20
Shapson, Stan M., and others. "An Experimental Study of the Effects of Class
Size." AMERICAN EDUCATIONAL RESEARCH JOURNAL 17 (Spring 1980):141-152.
Smith, Mary Lee, and Gene V. Glass. RELATIONSHIP OF CLASS-SIZE TO CLASSROOM
PROCESSES, TEACHER SATISFACTION AND PUPIL AFFECT: A META-ANALYSIS. San
Francisco, CA: Far West Laboratory for Educational Research and Development,
1979. ED 190 698.
Smith, Mary Lee, and Gene V. Glass. "Meta-Analysis of Research on Class Size
and Its Relationship to Attitudes and Instruction." AMERICAN EDUCATIONAL
RESEARCH JOURNAL 17 (Winter 1980):419-433.
Thompson, Sydney D. CLASS SIZE. School Management Digest. Burlingame, CA and
Eugene, OR: Association of California School Administrators and ERIC
Clearinghouse on Educational Management, University of Oregon, 1978. ED 154 471