Meta-analyses are systematic summaries of research that use quantitative methods to find the mean effect size (standardized mean difference) for interventions. Critics of meta-analysis point out that such analyses can conflate the results of low- and high-quality studies, make improper comparisons and result in statistical noise. All these…

In 2009, the government's Department for Education commissioned a team of researchers at NatCen Social Research to evaluate the effectiveness of the youth development/teenage pregnancy prevention programme 'Teens and Toddlers'. Previous studies had positive findings but had not been very rigorous in terms of methodology and methods used. We…