Philosophers say that the answer lies behind the question, but the simpler the question, the simpler the answer.
The principle of the problem tree is to treat a problem as the trunk and consider which factors it is related to. Each time you think of one, add a branch to the trunk. Each major branch can have further smaller branches, and so on, until all the factors involved in the problem are identified. A problem tree can help us reason deductively and break down problems, which is why it is also called a deductive tree, a logic tree, or a decomposition tree.
If an abstract problem is not broken down, the answer behind it is even less actionable. The value of a problem tree lies in its ability to break an abstract question down into smaller parts and make it concrete. The more concrete the problem, the more concrete the answer, and the more actionable it is.
For example, take poor academic performance. If the score mentioned here is the sum of scores across several major subjects, you can use the formula method of the MIS principle to break it down into specific subjects and see which subject is doing poorly. Then ask why that subject is doing poorly, using dichotomy to divide it into external problems and internal problems. For external problems, check whether the difficulty has increased, the pace has quickened, or the teacher has changed. For internal problems, see what your own issues might be—insufficient practice after class or a disorganized knowledge system. At this point the problem is fairly concrete; look at the answers behind them. If it's because the teacher changed, you can interact more with the new teacher and adapt to their teaching style as quickly as possible. If the knowledge system is disorganized, you can sort through the recent knowledge points, which may be more effective than blindly doing a few more pages of practice problems.
Summarization (Pyramid Principle, MECE Principle, Problem Tree)
The Pyramid Principle, the MECE Principle, and the Problem Tree are McKinsey's three famous structured tools. In fact, we can understand them as three emphases of the same decomposition mindset—one emphasizes expressing conclusions, one emphasizes the analytical approach, and one emphasizes finding answers—so the three can also interact and be used in combination. For example, when you use the pyramid as a thinking tool rather than an expression tool, the problem tree can directly become the skeleton of the pyramid. When you illuminate the core of the pyramid with a question, you give the problem tree a soul, and you can find the leaf you want. If you can also bring in the MECE Principle, you won't lose any leaf you want.