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Durham University

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Standard Deviation as an Outcome of Interventions: A Methodological Intervention, Education Endowment Foundation

A research project of the School of Education.


Interventions generally focus on the mean impact, but the impact of the spread of scores is also important.


The project is funded by the following grant.

  • Standard Deviation As An Outcome Of Interventions: A Methodological Intervention (£3602.00 from Education Endowment Foundation)


To establish updated procedure for measuring the change of SD


Theoretical, statistical


The report
It recommends the simple recording of percentage change in SD in the first instance, together with 95% Confidence Intervals. For meta-analyses it recommends the use of the log of the ratio of variances which is a metric with the suitable properties.


From the School of Education

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