What Is Federated Search and Why Is It Important

    What is federated search, and how it's different from traditional search engines? And more importantly, how can it improve your website and, thus also, user experience?

    Barbora Bončová
    Barbora Bončová Product Marketing Specialist
    What Is Federated Search and Why Is It Important

    According to Statista, we will have created more than 180 zettabytes of data by 2025. We have literally never had as much online information as we do now. On the one hand, that’s a great thing as it means we can find online information on any topic imaginable and in various forms – blog posts, YouTube videos, social media posts, FAQ guides, and so on.

    As part of their efforts to reach out to their potential customers, companies are also creating and sharing a lot of useful content. The problem is, the content is usually scattered around several websites, each with its own search engine and databases – and that definitely doesn’t make for a pleasant user experience.

    The good news are, there’s a way to let your users look through all available content on your website through a single search box and a single query only – Federated search.

    Find out what it is and how it can benefit your website.

    180 zettabytes

    We will have created more than 180 zettabytes of data by 2025. (statista.com)

    Federated search is a technique where the engine looks through a variety of sources at once and puts all relevant results into one place. With this, users can browse the content across all website sections simultaneously, rather than doing several searches on different parts of a company’s website – making it far more convenient to use than a regular search.

    A traditional search engine can only handle one data source at a time. So if your website users want to find a blog post, they typically need to use the blog search box. But if they needed to check something on a FAQ page, then they would have to use the knowledge base search instead. And what if they don’t know where the content might be published?

    That makes finding the information they need even more complicated as they would have to click through several pages and combine the results themselves – which is neither fast nor convenient. Federated search meanwhile can provide users with results from all pages at once and show them on a single user interface.

    Here’s an example that should make it clearer.

    Let’s say you are planning to buy a new smartphone. You already picked a model with the features you want and that is affordable, but before buying it, you want to read more about it on the manufacturer’s website. So you open the website and see that there’s actually plenty to read – the manufacturer has a detailed product page for all their products, a knowledge base, a blog website, a reviews section, and a discussion board as well.

    Now though, how can you find information about the specific phone model you picked? Using a traditional search engine means each website can only display results from its own pages – so the knowledge base can lead you to a product manual or FAQ but won’t show you customer reviews, while the blog will only give you a list of relevant articles in the results list. That means you have to look through all five websites separately. Not exactly convenient, right.

    With a federated search tool, the situation would look completely different. You would only need to type the phone model name into a single search box, and then you would get the results from all those five pages at once – having the phone specifications, the “Getting started” guide with a FAQ list, a few tutorial videos and also links to all reviews or discussion threads on one page.

    The federated search types can also sort the results according to content type, put those on separate results lists, and then display them on a single interface – making it even easier to locate specific content types.

    Federated search is made of two main elements:

    • A data index made of all available content in the company
    • A search function that crawlers the index for relevant information in response to a specific query.

    However, there are some differences when it comes to how the search function can interact with the data index.

    Search-Time Merging

    A search time merge (also called query time merging) is when the federated search tool passes the user’s query to all separate search engines added to the tool and then combines the results together to show the user a single result page. The most significant advantage of this method is that it’s the fastest and easiest to implement type of federated search – the content and data can be kept in separate indexes, and you don’t have to put the data into one specific format either.

    A major flaw here is that the search tool has to wait for every other engine to respond and send the results. If one of the search engines takes more time to process a request than the others, the entire search will take longer to complete.

    Index-Time Merging

    Another common type is index-time merging. It has the advantage over the query-time merging in that it has a much faster response time, thanks to a single index storing the entire data. The tool then searches through the index to find content matching the search query. Since index-time merging stores all the information in one place and doesn’t need to send requests to other engines, the search performance here is much better. Index-time merging type typically also comes with useful tools that can make the user experience even better, such as auto-complete and filtering.

    For the index-time method to work at full power though, you need first to create a single index with all of your content added to it and find a way to add different content types into the index. The index also has to be regularly updated, especially when you add new content to the website. As a result, implementing an index-time type is slightly more complex and time-consuming.

    Hybrid federated search uses both a main central index that keeps most of the information but also looks through additional online databases that are kept separately (for example, because it would be too difficult to add the content from the database into the main index). The results are then put together to create a final list.

    Compared to the search-time type, hybrid type have fewer places to check, so they show results faster. However, since the hybrid search still has to wait for a response from the separate databases, its response time is slower than the index-time merging with a single index would be.

    The Federated Search Interface

    This type works similarly to the search-time merging method (since it checks all data indexes separately), but instead of presenting the results in one combined list, it creates a separate result list per each type of content. For website visitors looking for content in a specific format, this method can be extremely useful. Additionally, website owners can here fine-tune the ranking of each of the content types, so that their website visitors get the most relevant results.

    Implementing this form requires the most work though. First, companies should consider how the interface should look to make it as user-friendly as possible for potential users. What’s more, not all available federated search solutions have the option to show different types of content in separate result lists, so you should double-check does the solution you want to implement has this feature.

    Using a federated search means users don’t have to click through multiple pages or compare results from several pages – all results are on one page and sorted by relevance or content type. That can significantly improve their search experience – and opinion about your company.

    But federated search can bring your company also other benefits:

    1. Increased customer satisfaction – and conversions rates

    As some studies show, conversion rates nearly doubled when people used on-site search and found what they wanted – federated search can be a great help here.

    Using it, website visitors can find exactly the information or content type they are looking for, even if they don’t know where exactly on the website the information might be. If they want the information to be in a specific type (say, they are looking for a video tutorial), then the federated search can guide them to those as well.

    If the searchers don’t know where exactly the content they are looking for might be, then to save their time, searchers might try to browse only one website – the one where they think they are most likely to find the information they need. By doing so, they might miss out on other useful content pieces though.

    Federated search can show results coming from all parts of your website though, even those hidden deep within a site or database. That way, the search tool can guide your website users to parts of your website they didn’t even think about checking – and make them stay on your website for longer.

    3. Improved Search Relevance

    Combining all of your content into one federated index will also significantly increase the relevance of the results your visitors will be getting. Simply – as there’s far more information indexed, that makes it easier for the engine to find and guide search users to the information they are looking for.

    Furthermore, Federated search allows you to fine-tune how high each type of content should appear in the results depending on what the website visitor is looking for to make the results more relevant – for example, putting product pages above blog posts.

    4. Far easier content management

    When you have several websites with separate content databases, keeping all content up-to-date might be pretty difficult – especially if different teams are working on your product page content and, say, your knowledge base.

    With federated search though, your employees have only one search engine to manage rather than several, so finding and updating the content inside it is much easier. Moreover, the central index can store content that doesn’t have its own index so that it can cover all content types and pieces created in your company.

    5. Far fewer security risks

    Besides making managing your content easier, federated search can help you secure your content databases as well. The fewer applications and databases that have to be managed by your team, the lower the risk that the data inside it might be damaged or compromised.

    And in case there will be any problems with how the search engine works, investigating and troubleshooting the issue will also be much faster if there’s only one tool to test rather than if you had 6 different engines to check.

    Benefits of Federated search


    Increased customer satisfaction


    Searchers can find content easier


    Improved search relevance


    Easier content management


    Fewer security risks

    Federated search can improve the search experience for both your visitors and your employees since it makes it much easier for them to find the information or content type they need. However, besides the long list of benefits, there are also a few challenges that companies trying to implement the federated search might encounter.

    For some types, the Implementation might be time-consuming.

    A query-time federated search can be implemented pretty quickly, but the other three will require some planning and preparations. In both index-time and hybrid types, you will need to create a single data index that will be used by the engine to process queries from users. The indexes also need to be regularly updated, especially if you are adding or deleting content or websites.

    As for the Interface method, you’ll need to spend some time designing your federated search user interface so visitors won’t have trouble using it.

    The federated search might have some trouble with ranking the results.

    The advantage of federated search is that you can add to it virtually any content type or form you are using in the company. If you have multiple data sources added to it though, then the federated engine might struggle when it comes to sorting the content in order, as each search engine may score relevance differently. That means you might need to spend some time fine-tuning how the federated engine will rank the content.

    The results page might show duplicated pages

    Multiple data sources increase the risk that some of the results will be duplicated – that might be especially the case in the search-time method. For example, the search engine might show a blog article and a PDF file that have exactly the same information as two separate results, confusing the users. You can prevent this problem by going through your data before it’s added to the index and removing any doubles.


    According to some studies, consumers who use search are 2.4 times more likely to buy, but only if they can find what they need with as little effort as possible. They can get exactly that with federated search.

    Instead of having to use a few separate engines and then comparing the results coming from each, users only need a single search, and then they have everything on one page, sorted by relevance or content type. And in times when everyone is in such a hurry, what could be more convenient for your users than a search solution that provides all the information they may need in a single click?

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