Is Small Better? The Effect of
Class Size on Pupil Performance
and Teaching Quality
Maurice Galton
Faculty of Education, University of
Cambridge UK
Presentation Seminar for
Education & Manpower Bureau,
Government of the HKSAR
13 December 2003
Some Contrasting Views
Studies and research into the effects of
class size have for the most part failed to
demonstrate that pupils necessarily do
better in small classes (OFSTED 1995)
The research suggests that for states,
districts and even schools, class size is a
very basic and significant variable in
improving educational outcomes (Egelson
et al 1995)
Some Early Evidence
• Meta-analysis of 77 studies of class size and
achievement (Glass et al. 1982) Pupils in classes of
20 taught for 100 hours would exceed performance of
pupils in classes of 40 by 60%.
• Effects are not linear (+ve for classes < 20; -ve for
classes > 30) Optimum effect in classes of 15 and
Grades 1 & 2.
• Larger effect sizes (>0.20) can be achieved through
paired work, co-operative learning and individualized
instruction for weakest pupils (Slavin 1989)
Teachers’ Views (Bennett 1996)
•
•
•
•
More time for individual instruction
Increase in pupil motivation
Less pupil misbehavior
Improved teacher-pupil personal
relationships
• More time for marking and assessment
• Less stress
Tennessee Student-Teacher
Achievement Ratio (STAR) Project
• 7000 pupils randomly assigned to small (13-17),
regular (22-25) and (regular + teaching assistant)
• Small classes did better from kindergarten to grade
3
• ethnic minority pupils did particularly well and
had highest self-concept scores
• effects still present when pupils moved to regular
classes from grade 4 to 6
(Nye et al. 2000)
Limitations of STAR
• Reanalysis of data using multi-level modeling
reduces effect sizes, shows school vs. size and
subject interactions
• No baseline measure so uncertainty about random
assignment
• Too narrow a range of classes: in many countries
class size is around 35
• Restricted range of school types (large, single age
entry)
(Goldstein & Blatchford 1997)
IoE Class Size Study
(Blatchford 2003)
• 9 Local Authorities,199 Schools, 330 classes
and 7142 pupils
• Baseline Literacy (reception entry),
standardized tests of literacy and maths
(reception & Y1) and National Tests (Y2)
• Systematic Classroom Observation
• 79 classes (10-20), 163 (21-25), 294 (26-30),
133 (31+)
• Teacher Opinion survey
Class size vs. Attainment (Reception Year )
Blatchford (2003)
0.8
0.6
Gain score
0.4
0.2
0
-0.2
12
18
24
-0.4
-0.6
-0.8
class size
30
36
Maths
Literacy
Class size vs. Attainment (Year 1)
Gain score
Blatchford (2003)
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0
-0.1
-0.2
Literacy
16
21
26
class size
31
36
Main Findings on Performance from
Blatchford (2003)
• Effects are largest in reception class
• Effects are still present for literacy in Y1 but
less pronounced by Y3
• In literacy both high, medium and low ability
groups benefit in classes of 25. Below this only
low ability pupils benefit
• In general, for mathematics effects are smaller
Teacher-Pupil Interactions [Number of
observations] (Blatchford 2003)
175
150
125
100
Small
Large
75
50
25
0
Task
Preparation
Procedure
Pupil-Pupil Interactions [Number of
observations] (Blatchford 2003)
50
40
30
Small
Large
20
10
0
Task
Procedure
Social
Disruption
Main Findings on Teaching from
Blatchford (2003)
• More one to one teaching
• Teacher more actively involved in whole class
or groups
• More task interactions
• Less task pupil-pupil interactions
Class Size and Teacher Interaction
Hargreaves & Galton (1998)
Teacher-Pupil Interaction Pearson
Correlation
Task questions
- 0.23
Challenging questions
- 0.25
Task feedback
- 0.34
Monitoring
+ 0.49 **
Routine Class Management
+ 0.37 **
Critical Control
+ 0.28
Sustained Interactions (Hargreaves & Galton 1998)
% observation
25
20
15
10
5
0
15
20
25
class size
30
Holywells Case Study
• A Suffolk secondary school in special
measures: Some 50% of pupils arrive in Y7 (11
year-olds) below national Literacy and
numeracy standard (Level 4).
• Pupils Level 3 (or below) at Key Stage 2
placed in 4 classes, size 20. Others in classes
of 30 or more.
• Integrated teaching approach for English,
maths and humanities. Reduced timetable for
science, arts and French.
Change in Level for English and
Maths
50
40
30
English
Maths
20
10
0
up 1
up 2
up 3
stay 3
stay 4
Other Changes
• Attribution change from “I’m in the small class
because I’m only Level 2” (ability) to “I can
cope in the Y8 bigger class if I work hard”
(effort)
• Despite fewer lessons in Y7 around 33% of
pupils are in the top sets in Y8 for Science and
French
• Improved behaviour, less truancy
• Critical of primary school experiences”Teachers
didn’t listen; didn’t explain properly.”
Cultural Contexts (Jin & Cortazzi 1998)
Western
Approach
Pacific Rim
Approach
Individual
Short spontaneous
Exchanges
Prepared extended
exchanges
Groups
Tasks planned
but spontaneous
talk & later class
feedback
Individual
teacher-pupil
exchanges
Speaker
orientated
Teacher
facilitated
Task and talk
prepared with
immediate
feedback
Whole class
responses
Whole Class
Principles
Listener
orientated,
Teacher
controlled
Pre and Post Literacy Hour
Questions (KS2)
80
70
60
50
closed
open
40
30
20
10
0
1976
1996
2001
2002
Some Key Questions
• Do teachers always maximize the benefits of smaller
classes? Is there a need for special training?
• Should other classroom interventions (e.g. peer tutoring,
use of teaching assistants) be viewed as an alternative to
class size reductions or a way of boosting their effects?
• Could initial teacher training offer opportunities of
working with half the class while class teacher takes the
remaining pupils elsewhere?
• Would flexible time tabling allow more pupils to
experience small classes ( Is half the time in a class half
the size more valuable?)
• When learning to learn is there a case for giving greater
priority to pupils in the 9-11 range or in transfer years?
Some Key References
Blatchford, P. (2003) The Class Size Debate: Is small
better? Maidenhead, UK. Open University Press.
Galton, M [Ed] (1998) ‘Class Size and Pupil
Achievement,’ Special Edition International Journal
of Educational Research, 29 (8).
Nye, B. et al. (2000) ‘The Effects of Class Size on
Academic Achievement: The results of the Tennessee
class size experiment’ American Educational Research
Journal, 37 (1): 123-151.
Finn.J.et al. (2003) ‘The “Why’s” of Class Size: Student
Behaviour in Small Classes, Review of Educational
Research, 73 (3): 321-368.