Finally, a recent meta-analysis (a quantitative review of research), involving large-scale experimental research (e.g., Lambert, 2007) has shown that formally monitoring client progress and providing...

Finally, a recent meta-analysis (a quantitative review of research), involving large-scale experimental research (e.g., Lambert, 2007) has shown that formally monitoring client progress and providing feedback to the practitioner, as in singlesystem designs, not only can reduce deterioration but also can have a positive effect on overall outcome. Now that is an enormous boost to the importance of evaluation-informed practice using single-system designs.