Relevance score (_score) in Elasticsearch - Mini Project: Build & Apply

Understanding Relevance Score (_score) in Elasticsearch

📖 Scenario: You are building a simple search feature for a small online bookstore. You want to understand how Elasticsearch ranks search results using the _score field, which shows how relevant each book is to the search query.

🎯 Goal: Learn how to perform a basic search query in Elasticsearch and see how the _score helps rank the results by relevance.

📋 What You'll Learn

Create an Elasticsearch index with sample book data

Add a search query to find books by title

Retrieve and display the _score for each search result

Understand how _score affects the order of results

💡 Why This Matters

🌍 Real World

Search engines use relevance scores to show the most useful results first, like when you search for books, products, or articles online.

💼 Career

Understanding _score helps developers build better search features that give users the best matches quickly.

1

Create an Elasticsearch index with sample book data

Create an index called books and add these three documents with fields title and author: {"title": "Learn Elasticsearch", "author": "Alice"}, {"title": "Mastering Search", "author": "Bob"}, {"title": "Elasticsearch Basics", "author": "Charlie"}.

Elasticsearch

# Use Elasticsearch API to create index 'books' and add 3 documents
# Your code here

Need a hint?

Use the PUT method to add documents to the books index with the exact titles and authors given.

2

Add a search query to find books by title

Create a search query that looks for the word Elasticsearch in the title field of the books index.

Elasticsearch

PUT /books/_doc/1
{
  "title": "Learn Elasticsearch",
  "author": "Alice"
}

PUT /books/_doc/2
{
  "title": "Mastering Search",
  "author": "Bob"
}

PUT /books/_doc/3
{
  "title": "Elasticsearch Basics",
  "author": "Charlie"
}

# Add a search query for 'Elasticsearch' in the title field below
# Your code here

Need a hint?

Use the GET method with _search and a match query on the title field.

3

Retrieve and display the _score for each search result

Modify the search query to include the _score field in the results and show it for each matching document.

Elasticsearch

PUT /books/_doc/1
{
  "title": "Learn Elasticsearch",
  "author": "Alice"
}

PUT /books/_doc/2
{
  "title": "Mastering Search",
  "author": "Bob"
}

PUT /books/_doc/3
{
  "title": "Elasticsearch Basics",
  "author": "Charlie"
}

GET /books/_search
{
  "query": {
    "match": {
      "title": "Elasticsearch"
    }
  }
}

# Add code to show _score for each result below
# Your code here

Need a hint?

Add "explain": true to the search request to see the _score details for each hit.

4

Print the search results with their relevance scores

Run the search query and print the title and _score of each hit in the results.

Elasticsearch

PUT /books/_doc/1
{
  "title": "Learn Elasticsearch",
  "author": "Alice"
}

PUT /books/_doc/2
{
  "title": "Mastering Search",
  "author": "Bob"
}

PUT /books/_doc/3
{
  "title": "Elasticsearch Basics",
  "author": "Charlie"
}

GET /books/_search
{
  "query": {
    "match": {
      "title": "Elasticsearch"
    }
  },
  "explain": true
}

# Print the title and _score of each hit below
# Your code here

Need a hint?

Look at the search response hits and print each hit's _source.title and _score.