Semantic Index

What is Semantic Index? (M365 Copilot)

Semantic index is a map of your individual and company data that is created by Copilot. It is a core part of the Copilot System, which is an AI-based work assistant that helps you with tasks like writing, presenting, searching, and more. Semantic index helps Copilot understand your data better and provide more relevant and personalized responses to your queries or prompts.

How does semantic index benefit Copilot users?

Semantic index enhances the Enterprise Search (Microsoft Search) results for Microsoft 365 E3 and E5 customers, whether they are using Copilot or not. For example, when you ask Copilot about the “March Sales Report”, it doesn't simply look for documents with those words in the file name or body. Instead, it understands that “sales reports are produced by Kelly on the finance team and created in Excel”. And it uses that conceptual understanding to determine your intent and help you find what you need. (see NLP)

Semantic index also enables more conversational, multi-turn interactions with Copilot. For instance, you can ask follow-up questions like “Who edited it last?” or “How does it compare to February?” and Copilot will use the semantic index to keep track of the context and answer accordingly.

How can you enable semantic index for your organization?

Semantic index is a new capability in Microsoft 365 E3 and E5 that will start rolling out to customers 2023. To use semantic index, your organization must meet some technical requirements and have some features enabled.