Prompting guide
4 minute read
This is aimed at Gemini, but similar principles can be applied to other AI assistants too.
A prompt is the message or instruction you give Gemini to get a response.
Your prompt can include information you paste in for context or reference, such as a text excerpt. It can also include uploaded documents or pictures.
Prompts are the most important factor in getting good quality responses from AI. Writing prompts is a skill, and it can take a little practice.
Be specific
Gemini has a lot of knowledge and ability beneath the surface, but it will only work from exactly what you give it. You need to provide context and clear, explicit instructions.
When you ask Gemini to do something like write an introduction to Shakespeare’s life, it will draw on all the information that Google gave it to train on. Likely including facts, quotes, and other details about Shakespeare’s life and works.
However, AI takes your prompt at face value—without context, it has to make assumptions and will produce the most generic interpretation of your request. Adding detail (your audience, purpose, length, tone) reduces those assumptions and gets you closer to what you actually need.
Example of a vague prompt:
Write something about Shakespeare.
A more specific prompt:
Write a 150-word introduction to Shakespeare’s life suitable for Year 7 pupils, focusing on his childhood and early career. Use simple language and include 2–3 interesting facts that might surprise pupils.
If you want a response tailored to just the information in a specific resource, give Gemini the resource to reference.
Use the PARTS framework
Using a framework can help you learn to structure your prompts to get high-quality responses.
PARTS is a framework recommended by Google for Education with five elements: Persona, Act, Recipient, Theme, and Structure.
| Element | What | Why |
|---|---|---|
| P: Persona | Gemini’s role | Guides the expertise and perspective |
| A: Act | Clear description of the task | Use action verbs such as create, summarise, explain, rewrite, analyse, or compare. |
| R: Recipient | Who the response is for | Helps set appropriate tone, vocabulary, and complexity. |
| T: Theme | Topics, context, or background information | Helps Gemini focus on the right information. |
| S: Structure | The format you want | Guides the length, format, and organisation of the response. |
Worked example
A Year 6 teacher wants to create a model text for pupils to analyse before writing their own persuasive letter.
| Element | Example |
|---|---|
| P: Persona | An experienced KS2 primary school teacher familiar with the KS2 English curriculum |
| A: Act | Write a model persuasive letter, written from a pupil’s perspective |
| R: Recipient | Year 6 pupils (aged 10–11) preparing to write their own persuasive letter |
| T: Theme | Persuasive writing techniques: rhetorical questions, the rule of three, and direct address |
| S: Structure | Three paragraphs, with a short annotation beneath each one identifying the techniques used |
Assembled prompt:
Act as an experienced KS2 primary school teacher familiar with the KS2 English curriculum. Write a model persuasive letter for Year 6 pupils (aged 10–11) that they can analyse before writing their own. The letter should be written from a pupil’s perspective, arguing for a school trip to a local nature reserve. It should demonstrate rhetorical questions, the rule of three, and direct address. Organise it into three paragraphs, with a short annotation beneath each one identifying the techniques used.
Iterate and refine
You rarely need to get everything right in your first prompt. If the response isn’t quite what you wanted, just ask Gemini to adjust it—this is often quicker than rewriting your prompt from scratch.
Some examples of follow-up prompts:
- “Make it shorter”
- “Rewrite this for Year 9 instead”
- “Use a more formal tone”
- “Turn this into a bullet-point list”
- “Add a short introduction”
You can keep refining in the same conversation until you’re happy with the result.
New task, new chat
Gemini creates its next response based on everything in your current chat conversation.
When you have a new task or topic, start a new chat.
Changing topics or mixing unrelated tasks in a single chat can pull Gemini’s responses off course—earlier messages start to colour how it interprets new ones.
Start fresh if quality drops
AI can only hold so much information in its working memory (called its context window).
These can be very large (thousands of pages of text), but are not infinite. If you have an extremely long chat or provide a lot of long documents all at once, Gemini may struggle to generate a good-quality response. If that happens, starting a fresh chat often helps.
Quick reference
- Be specific: include your audience, purpose, length, and tone
- Use PARTS: structure prompts with Persona, Act, Recipient, Theme, and Structure
- Iterate: if the first response isn’t quite right, follow up: “make it shorter”, “rewrite this for Year 9”
- New task, new chat: start a fresh conversation when moving to an unrelated topic
- Fresh chat if quality drops: long chats can affect response quality
- Check for accuracy: remember to always verify facts, dates, and quotes before using them