The document discusses key aspects of designing effective problems for problem-based learning (PBL). It states that PBL problems should: [1] promote higher-order thinking by requiring students to recognize knowledge gaps when first analyzing the problem; [2] require students to search for new knowledge and understanding to find a solution; and [3] provide context for connecting new ideas to prior knowledge. The document also notes that effective PBL problems should motivate learning through real-world relevance and open-ended questions.