Decoding the 4 Types of Federated Search

In the age of information overload, finding relevant data amidst the digital chaos can be a herculean task. Organizations today grapple with a growing online presence, encompassing websites, databases, and content repositories that often leave users feeling lost. 

‍Federated search is the superhero that swoops in to save the day, delivering a unified search experience that enables users to access information from multiple sources simultaneously, without visiting each source separately. Let's delve into the concept of federated search, explore the four different approaches to implementing it, and examine real-life examples that showcase its value.

Understanding federated search 

Federated search involves indexing and searching multiple information sources simultaneously. When a user submits a search query, the federated search system sends the query to each of the indexed sources. 

Each source then retrieves its own results based on the query and sends them back to the federated search system. The federated search system then aggregates the results from all the sources and presents them to the user in a single, integrated view. This process makes it easier for users to find relevant information without navigating multiple sites or databases.

A common real-life application of federated search can be found in research libraries. Academic institutions often subscribe to numerous databases and electronic journals to provide their faculty and students with the information they need.

In one of the studies, authors compared the search effectiveness of federated search tools to conventional library resources and Google Scholar. They found that the use of discovery services led to a significant increase in full-text article retrievals compared to using individual databases – further supporting the point that federated search enables researchers to search across all these databases simultaneously, saving time and improving the research process.

The 4 approaches to federated search 

Depending on your search and business goals, you can choose one of the 4 types of federated searches mentioned below.

• Search time merging (or query time merging)
• Index time merging
• Hybrid federated search
• Federated search interface

Let's dive deep into them!

Search time merging (or query time merging)

Search time merging involves sending a user's search query to multiple indexed sources simultaneously. Each source processes the query independently and returns its results to the search system. 

The search system then combines and ranks the results from all sources, presenting a unified list of results to the user. This approach is highly efficient in providing up-to-date information but may be slower than other methods due to the time required to process queries across multiple sources.

As an example, Kayak is a metasearch engine for travel that employs search time merging to deliver comprehensive search results. When users search for flights or accommodations, Kayak simultaneously sends the query to multiple travel websites, such as airline and hotel booking platforms. It then aggregates the results in a single list, enabling users to compare prices, amenities, and schedules from different sources efficiently.

Index time merging

In index time merging, the search system combines and indexes information from multiple sources before a user submits a query. When users search, they query a single, unified index rather than multiple sources. This approach offers faster search results since the system doesn't need to query each source in real-time. However, it requires more effort to maintain the index and can result in less up-to-date information compared to search time merging.

Google's custom search engine exemplifies index time merging. Website owners can create a custom search engine that indexes content from specific websites. By creating a unified index from multiple sources, Google ensures that users searching through the custom search engine query this single, consolidated index rather than multiple sources. This method offers faster search results and a streamlined user experience.

Hybrid federated search

Hybrid federated search combines elements of both search time merging and index time merging. This approach can involve creating a unified index for some sources while querying others in real-time. Hybrid federated search offers a balance between the speed of index time merging and the up-to-date information provided by search time merging. It is particularly useful when dealing with a mix of static and dynamic content sources.

Ecommerce platforms like Amazon can use hybrid federated search to deliver relevant search results to users. For example, product information and customer reviews can be indexed and merged for faster search results, while real-time querying of external sources like pricing and inventory data can ensure the most up-to-date information is displayed. This combination of approaches enables Amazon to deliver accurate and efficient search results to users.

Federated search interface

A federated search interface uses a single search interface to query multiple sources without merging the results. Instead, the user receives results from each source separately, allowing them to easily identify the origin of the information. This method is useful when the user needs to see results from different sources separately, but it can be less efficient and may require more effort to compare and analyze results.

An example of this kind of federated search can be seen at the WorldWideScience.org portal. The website employs a federated search interface to provide access to scientific information from databases and portals worldwide. 

When users enter a search query, the system queries multiple sources, such as national libraries, research institutions, and government databases. The results are displayed separately for each source, enabling users to identify and compare information from different origins easily. While this approach may not be as efficient as merging results, it provides valuable context and transparency to users.

Breaking down information silos with federated search

Federated search is a powerful tool that can streamline the search experience for users and improve access to information scattered across multiple sources. Depending on your business goals, you can choose from search time merging, index time merging, hybrid federated search, or federated search interface to provide the best search solution for your users. 

As search and discovery experts Zevi can help you navigate these options and implement the most effective federated search solution for your business. Get in touch with our team today to learn more about how federated search can benefit your organization and enhance the search experience for your users.

Don't wait—contact Zevi for a demo today and explore the potential of federated search for your enterprise or D2C business.