How do title, content field, and keyword field in semantic configuration impact semantic search?

Question

I'd like to better understand how semantic search makes use of the semantic configuration when doing the search.

In https://learn.microsoft.com/en-us/azure/search/semantic-how-to-query-request?tabs=portal%2Cportal-query, it lists the properties you need to set:

• Title field
• Content field
• Keyword field

I understand what these are, but I'm more curious on how they are used to do a semantic search. Is Azure appending them all together and then doing a semantic similarity comparison against the query? Why are keyword fields important for a semantic search, that seems more relevant to the lucene search it does initially.

Understanding how Azure makes use of these fields for semantic search will help me better tailor my search indices for better retrieval. Thanks!

Answer 1

@Sam Baird Thanks for asking great question! So, to elaborate-

All those fields will be appended and prioritized as ordered in the semantic configuration.

You can choose the order according to what matters most for your scenario.

As explained in Configure semantic search - Azure Cognitive Search | Microsoft Learn the keywords can be used in case customer categorizes the doc while indexing in some fashion or you need to add anything that is relevant for your scenario for the specific doc.

For example, you might have a set of areas that have been identified and important for your use case that you may need to prioritize and add to the semantic query since not determined from the document content or title.

This is not a requirement. Keyword field has been added based on several customer requests for specific use cases.

Hope this helps.

Let us know if further query or issue remains.