Book excerpt: Schools are constantly under pressure to keep up with the pace of changes in society. In parallel, societal demands for what schools should teach are also constantly changing; often driven by political agendas, ideologies, or parental pressures, to add global competency, digital literacy, data literacy, environmental literacy, media literacy, social-emotional skills, etc. This “curriculum expansion” puts pressure on policy makers and schools to add new contents to already crowded curriculum.