Metacognition is recognized as an important tool in supporting teaching and fostering active learning. In this PhD dissertation-based monograph, the contributions of three metacognitive instructional methods in learning primary science in non-ideal classrooms are provided. In spite of the complexity of the construct, this book provides that simple and innovative metacognitive instructional strategies can be easily designed and successfully employed by marginally trained teachers. Simple metacognitive instructional strategies become essential elements that promote students active and conceptual change learning without teachers feel that they are making fundamental changes in their teaching tradition. The book can serve as an important reference for those who need to design simple but effective metacognitive instructional strategies in teaching science across grade levels.