This self discovery stays with students throughout their lifetimes while memory fades. If students are not doing hands-on science, they are not doing science. Science is a process and if students are not actively engaged in the process, they are not doing science. Most science classes in elementary school teach the vocabulary of science and nothing else. Study after study has shown the value of hands-on learning.
Students are motivated, they learn more, even their reading skills improve.
Learning by well-planned activities and experiences in a well engineered program is a quality instructional approach. Most students live in an authoritarian world with little or no opportunity to practice decision-making because nearly everyone tells students what to do and when to do it. We continually graduate students who do not yet have the ability to set up a simple experiment with controlled variables, collect and interpret evidence, or make correct interpretations based upon that evidence. In this way, special benefits are not awarded to those who, by virtue of their wealth or background, have a greater number of experiences under their belts. However, when a student personally germinates seeds in the dark and finds that they grow taller than seeds grown in the light, it has irrefutable evidence from a personal experience that plants do not need light to grow.