Claim 1: School leadership is second only to classroom teaching as an
influence on pupil learning
This claim will be considered controversial by some. We could have claimed simply that school leadership
has a significant effect on pupil learning, but our choice of wording captures the comparative amount
of (direct and indirect) influence exercised by successful school leaders. Leadership acts as a catalyst
without which other good things are quite unlikely to happen. Five sources of evidence justify this claim.
While the middle three sources we identify are quite compelling, it is the first and fifth sources that place
leadership in contention with instruction.
Five sources of evidence
1. The first justification for this claim is based upon primarily qualitative case study evidence. Studies
providing this type of evidence are typically conducted in exceptional school settings.
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. Such settings
are believed to contribute to pupil learning and achievement that is significantly above or below
normal expectations (defined, for example, by research on effective schools based on comparing
value-added similarities and differences among high and low performing schools). Studies of this
type usually report very large leadership effects, not only on pupil learning but on an array of school
conditions as well.
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What is lacking in this evidence, however, is external validity or generalisability.
2. The second type of evidence about leadership effects is from large-scale quantitative studies of
overall leader effects. Evidence of this type reported between 1980 and 1998 (approximately four
dozen studies across all types of school) has been reviewed in several papers by Hallinger and
Heck.3
These reviews conclude that the combined direct and indirect effects of school leadership
on pupil outcomes are small but educationally significant. While leadership explains only five
to seven per cent of the difference in pupil learning and achievement across schools (not to
be confused with the typically very large differences among pupils within schools), this difference
is actually about one-quarter of the total difference across schools (12 to 20 per cent) explained by
all school-level variables, after controlling for pupil intake or background factors.
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The quantitative
school effectiveness studies providing much of this data indicate that classroom factors explain
more than one-third of the variation in pupil achievement.
3. A third type of research about leadership effects is, like the second type, large scale and quantitative
in nature. However, instead of examining overall leadership effects, it enquires about the effects
of specific leadership practices. A recent meta-analysis,
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for example, identified 21 leadership
responsibilities and calculated an average correlation between each one and the measures of pupil
achievement used in the original studies. From this data, estimates were made of the effects on
pupil test scores. The authors concluded that a 10 percentile point increase in pupil test scores
would result from the work of an average headteacher who improved her demonstrated
abilities in all 21 responsibilities.