Explain a concept at different levels with AI — and check it
Turn one textbook definition into explanations for two reader levels, then count missing key terms with a script and tag analogies to catch bad simplifications.
"Inside plant cell structures called chloroplasts, light energy breaks apart water and carbon dioxide molecules and rearranges them." That line came back when Gemini got the one-line prompt "Explain photosynthesis simply." Light energy does split water, but carbon dioxide is not broken apart by light — and nothing in the answer says who it was written for. Below, the same concept is requested again with the definition and the readers spelled out, and the results are compared.
[1] Paste the definition from the textbook. It is the reference for checking whether the simplified version dropped a condition. The example is a generic textbook-style sentence.
Photosynthesis is the process in which green plants use light energy in their chloroplasts to make glucose from carbon dioxide and water, releasing oxygen.[2] Put the role and the rules at the top of the prompt. Google's Gemini prompt design guide recommends placing the persona and essential constraints in the system instruction or at the very beginning of the prompt, and gives length limits like "in one sentence" as an example of a constraint. The five-sentence limit and the tagging rules below play that role.
You are a teacher who re-explains science concepts at the learner's level. <definition>{one paragraph: the textbook definition}</definition> Explain the definition above separately for these two readers:1. {A 12-year-old in 7th grade}2. {A college student in an intro biology course} Rules:- Each explanation is 5 sentences or fewer.- Both explanations must include every one of these: {light energy, chloroplast, carbon dioxide, water, glucose, oxygen}.- If you use an analogy, start that sentence with [analogy], and in the very next sentence state in one line how the analogy differs from reality.- If you add a fact that is not in the definition, end that sentence with [added].- After each explanation, write 2 check questions at that level, under a line "Check questions". Put all answers together in a final "Answers" section.- No greeting or closing remarks.- Use "### 1." and "### 2." as the section headings.[3] The prompt was run twice and compared with the one-line prompt.
| "Explain simply" | Prompt above (2 runs) | |
|---|---|---|
| Reader | Not set | 7th grade · intro college |
| Six key terms | All present | All present at both levels |
| Analogy | "a plant baking a cake", unmarked | One per run at the 7th-grade level, followed by how it differs |
| Facts beyond the definition | Unmarked (chlorophyll, stomata, starch) | Tagged [added] — 3 sentences per level |
| Check questions | None | 2 per level, with answers |
[4] Count missing terms with a script instead of by eye. check.py reads each ### 1. / ### 2. section up to the check questions and prints missing terms and tag counts (case-insensitive substring match).
$ python3 check.py level.en.out.1.txt "light energy" chloroplast "carbon dioxide" water glucose oxygen1. missing: - [added]3 [analogy]12. missing: - [added]3$ python3 check.py --whole naive.en.out.txt "light energy" chloroplast "carbon dioxide" water glucose oxygen(whole answer) missing: -"missing: -" means the words are there, not that they are used correctly. The one-line answer passes this check and still contains the wrong sentence quoted at the top.
[5] Read the sentences that carry a tag, and the ones that don't. In both runs the 7th-grade version made the chloroplast do the plant's job:
Powered by absorbed light energy, the chloroplast takes in water from roots and carbon dioxide from the air. [added]Roots and leaves take in the raw materials; the chloroplast is inside the leaf cell. Tags are also coarse: run 2 tagged "the plant releases oxygen gas into the atmosphere as a byproduct [added]", though releasing oxygen is in the definition. Treat a tag as "check here", not "wrong here".
[6] Solve the check questions and compare with the answers. The 7th-grade answers (chloroplast, oxygen, carbon dioxide and water) are inside the definition from step 1. The college answers (light-dependent reactions, thylakoid membranes, stroma, Calvin cycle) are not, so check them against the textbook. Watch the answer format too: run 1 numbered all answers 1 to 4 instead of grouping them by level, which makes it easy to match the wrong question.