Problem solving: What are the important questions?

Problem solving research is in need for re-thinking main questions. The purpose of this paper is a stock-taking of some of the identified problems, to discuss potential remedies for them, and to look for future perspectives. I see three areas for discussion: (1) What are the phenomena to be explained? (2) What methods should be used? What methodology is appropriate to the subject? (3) What is the progress in theory since the legendary work from Newell and Simon (1972)? What can we expect from new data sources? How can we relate data to theoretical assumptions