It means that both curriculum and instruction should begin with problems, questions, and dilemmas. Knowledge can be viewed as knowing or doing. Knowledge as knowing can be produced by reason, abstracted from experience, and potentially certain. Knowledge as doing involves interacting with the world filled with uncertainty and changing circumstances that cannot be controlled. The level of reflective inquiry and problimatizing depends more on the student and the culture of the classroom than on the task.
Problem solving requires higher order thinking skills.
Students are asked to evaluate, justify, and reason when tackling a problem. These are the skills we as teachers want to enhance in our students.