2.2.1. File and Document Grounding
When you provide a file or document as context — by attaching it to your prompt or using @mention to reference it — Copilot reads that file and uses it as the primary source for its response. This is the most reliable form of grounding for accuracy.
How to reference files in a prompt:
- Type
/in the Copilot prompt field to browse and select files - Use
@filenameto reference a specific file by name - Attach a file directly when the interface supports it
What changes when you ground with a file:
| Without File Grounding | With File Grounding |
|---|---|
| Copilot answers from general training | Copilot answers from the specific document |
| Higher fabrication risk on specific facts | Answers traceable to the source document |
| Generic, applicable-to-anyone response | Response specific to your document's content |
| No citations possible | Can cite specific sections |
Example: Asking "What are our Q3 sales targets?" without context will produce a generic answer about how to think about sales targets. Asking the same question with your Q3 planning spreadsheet attached will produce an answer from that specific spreadsheet.
⚠️ Exam Trap: Referencing a file does not mean Copilot will only use that file. Copilot may still draw on its general training for context around the file's content. If you need Copilot to answer exclusively from a file, make that explicit in your prompt: "Using only the attached document, summarize..."
Reflection Question: A user asks Copilot to help draft a proposal using their company's standard proposal template. What should they do to ensure Copilot's output matches their organization's specific format rather than a generic proposal format?
