Neither student-centered learning nor hands-on learning is as effective when children confront concepts that are not applicable to their own lives. This supports the idea that knowing a concept is being able to apply it; indeed, scientific information and its applications do become more meaningful when children can tie them to their real life experiences. Children engaged in authentic problem-based learning apply their science knowledge to questions they have about why things happen in their world, and they discuss the social ramifications that are often associated with scientific concepts.
Sometimes logistics prevent teachers from placing children in real-life situations to study. In these instances, kids can use computer programs, videotapes, or videodisks to study authentic problems. In addition, children can answer their questions about real-world phenomena by using the Internet to collect data. However the teacher facilitates the children's investigations, the activities shouldbe nested in authentic, real-life problems.
A Guide to Problem Based Learning: http://www.startlocal.com.au/articles/educational_problem_learning.html