These cannot be taught out of a textbook, but must be activated through experience."[4] James G. Greeno (2006) has associated project-based learning with the "situated learning" perspective[5] and with the constructivist theories of Jean Piaget. Blumenfeld et al. elaborate on the processes of PBL: "Project-based learning is a comprehensive perspective focused on teaching by engaging students in investigation. Within this framework, students pursue solutions to nontrivial problems by asking and refining questions, debating ideas, making predictions, designing plans and/or experiments, collecting and analyzing data, drawing conclusions, communicating their ideas and findings to others, asking new questions, and creating artifacts."[6] The basis of PBL lies in the authenticity or real-life application of the research.