With the 21st century came new ideas and goals in education creating so a whole new educational landscape .

In order as educators and students to stay motivated in this new system, it is necessary to focus on methods and practices that are evidenced based.

As with the testing of new drugs, evidence-based teaching methods are derived from controlled trials. When several of these studies are compared, and their conclusions combined, we get a meta-study or meta-analysis.

Two sources of meta-analyses in education include: Visible Learning from a team in New Zealand under John Hattie and Classroom Instruction that Works from a Colorado, USA team under Robert Marzano.

Although Hattie's work does not exactly mirror this list, the main reason is that the New Zealand study looks at everything related to education, including family effects and changes to the curriculum, while the Colorado study looked only at classroom methods. There are, however, no incompatibilities and most of Marzano's top-ten appear high on Hattie's list.