private-schools-full-report

3. Methodology
The overall strength of evidence for each testable assumption was given by assessing the
ratings across the four criteria as described below:
Weak (overall strength): If a weak rating appeared in any of the categories, then the
body of evidence was rated as weak overall.
Moderate (overall strength): If two or fewer categories were rated strong and the
remainder of categories were rated medium, then the body of evidence was rated as
moderate overall.
Strong (overall strength): If all categories were rated strong or three were rated strong
with one rated medium, then the body of evidence was rated strong overall.
Appendix 8 presents the assessment of overall relative strength of evidence for each
assumption in relation to the rating of the categories of quality, size, context and
consistency.
3.5 Limitations of the methodology
The following methodological limitations of the rigorous review are highlighted and need
to be taken into account:
1. The review is limited by the level of detail given by authors in the studies
reviewed. Authors of the studies reviewed did not consistently provide information
on the types of private schools, including fee level (e.g. whether LFP or for-profit),
primary, middle or secondary school, urban, peri-urban or rural. Additionally, only
studies that were captured under the key search terms were included in the
review, this may exclude any studies where authors do not use the term ‘private’
to describe fee dependent schools.
2. Due to the large volume of available material beyond the scope of the time and
resources available for the review, the evidence base reviewed was narrowed down
by applying thresholds of relevance and quality, and by focusing attention on
DFID’s priority countries and on completed material published from 2008. The
findings need to be understood in the context of these limits to the set of
literature reviewed. Earlier relevant research and that conducted in non-DFID
priority developing countries are cross-referenced in footnotes where appropriate
to signpost the reader to related material not included in the review. Given the
focus on quality published research in this rigorous review, it may not capture all
of the current policy debate about private schools.
3. Rigorous measures were applied in order to reduce researcher bias and to enhance
the review’s quality and objectivity. The review process was subject to continuous
scrutiny by the advisory panel, and cross-checked, edited within the research
team, and reviewed by external independent experts. Protocols were used to aid
the consistency of approach across the team in the assessment, extraction and
synthesis of the evidence. However it is important to note that, even with the most
rigorous process, researcher subjectivity cannot be completely eliminated.
4. A rigorous and transparent protocol was followed in order to arrive at the overall
strength of evidence. Although this took into account many dimensions including
quality and size of studies, context and consistency, the strength of evidence is a
relative term that should be understood in the context of the review. These
indicators of strength and of positive, negative and neutral findings do not always
capture nuances in the evidence and limitations of methodology which suggest
caveats to our confidence. Where this is the case, it is highlighted in the text.
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