The effectiveness of changes will depend not only on the compliance of schools with new policies, but on the way educational institutions respond to incentives (and directives) for improvement (Elmore, 2008). The institutional responses can be influenced by different factors that are often related to the ability and quality of school leadership. These schools exist in a myriad of contexts with a myriad of specific conditions - language groups, income groups, community cohesion and mobility, etc.