Knowledge in science have been treated as „serious“ and solid knowledge allowing to comprehend the basics and laws of natural world of physics, chemistry and biology and opening venues to prestigious professions in medicine or engineering. Different countries are anxious to follow the achievements of their youngsters in PISA tests, as if „measuring“ the temperature of their systems of education as well as related prospective economic growth. It is also usual to relate knowledge and achievements in science to the formal system of school or university education. . John H. Falk and Lynn D. Dierking present research based arguments about the importance of elective non-formal education in after-school activities, clubs or even self-directed learning in exponential growth of knowledge in science rather than in increasing the hours of formal science education at school. Non-formal adult and youth education allows interesting and attractive forms of learning and gaining solid knowledge in sciences that later reflect in test results of adult science literacy. You will find more about the importance and arguments of non-formal science education in the article.