Perhaps the most sweeping federal initiative to influence research
practice is the Elementary and Secondary Education Act referred to as No
Child Left Behind (NCLB) (2001). This legislation requires the use of
scientifically-based research to improve educational practice. The Act
defines scientifically-based research as “rigorous, systematic, and objective
procedures to obtain valid knowledge” about an educational program or
practice. The expectation is that evaluations will be conducted of these
programs using experimental and quasi-experimental methods to assess
the impact of the programs with respect to intended results (see Chapter
4). Randomized designs and those using thoughtful matching techniques
are the preferred research approach in NCLB (Slavin, 2002).