There's no denying the power and popularity of the Google search engine, and in comparison to other similar search engines such as Bing, where results are based on page rankings and algorithms, they excel.

But there are other ways to search the web, using what are known as semantic search engines. Using a semantic search engine will ensure more relevant results based on the ability to understand the definition of the word or term that is being searched for, rather than on numbers. Semantic search engines are able to understand the context in which the words are being used, resulting in smart, relevant results.

This is a list of the top 7 search engines to get you started in the world of semantic searching.

Kngine

semantic search engine

Kngine's search results are divided into either web results, or image results. They are preceded by information about the search term, known as 'Concepts.' For example, searching for the iPhone 3GS will be preceded by the device's specs. Searching for a film will be preceded by information about the film, links to trailers, reviews and quotes. Searching for a city will be preceded by information about the city, local attractions, events, weather and hotels.

Kngine currently contains more than 8 million Concepts, and that is where the site's strength lies.

semantic search engine

You can quickly share results from Kngine on Twitter, Facebook, Digg and Delicious and Kngine can be set as your default search engine if you are using FirefoxGoogle Chrome or Internet Explorer.

Hakia

semantic search engine

Hakia's search results are divided into Web, News, Blogs, Twitter, Image and Video, and can be re-listed according to relevance or date. Depending on the search term, results can also include an excerpt from its Wikipedia entry. They also have what are labeled 'Credible' results that come from trusted sources.

Each link is followed by a text excerpt, giving you an idea of what you would find in that search result.

Hakia can also be added to the list of search engines included in your browser's quick search bar.

[NO LONGER WORKS] Kosmix

Kosmix has a start page which is more elaborate than the most of the other semantic search engines listed here - with popular content featured on its front page from Yahoo Buzz, Digg, YouTube, Fark, Flickr, and a ton of other sources, making it a hybrid aggregator and search engine, with results included from Google and Bing.

Despite this, it is still considered a semantic search engine because it uses semantics in an attempt to link data from all over the web, giving you relevant search results.

When it comes to the search results themselves, they are divided into Video, Web, News & Blogs, Images, Forums, Twitter, Amazon and Facebook. In the case of some results, such as searching for the iPhone 3GS, you will also find Fix-It and How-To Guides.

semantic search open source

Kosmix is one of the few semantic search engines which does contain sponsored content, but that is a small price to pay for the wealth of information you can find all in one place.

DuckDuckGo

semantic search open source

DuckDuckGo is a feature-rich semantic search engine, that gives you countless reasons to leave Google behind. Searches are divided into a classic search, information search, shopping and their own spin off from Google, "I'm feeling ducky."

If you search for a term that has more than one meaning, it will give you the chance to choose what you were originally looking for, with its disambiguation results. For example, searching for the term Apple will give you a long list of the possible meanings - including the fruit, the computer company, the bank and many others.

semantic search open source

You can also set DuckDuckGo as your default search engine, and still get results from other search engines without ever leaving the page using their !bang feature. You can search any major site such as Google, YouTube, Amazon and eBay by preceding the search term with "!youtube" or "!google" and so forth - and you will automatically be taken to a list of search results from that service. It also works with keywords such as weather, images, and lyrics.

A full list of the !bang keywords can be found here.

DuckDuckGo features 'Zero-click info,' where like with Kngine, information about the search topic precedes the search results.

what is semantic search

Other features on DuckDuckGo include category pages, keyboard shortcuts, customisations, and it can detect calculations, WolframAlpha conversions, colour codes and much more.

Evri

Evri, like Kosmix, has an information rich landing page, with top news stories from around the web, which you can scroll through using the navigation at the top of the page.

Search results can be filtered into Articles, Quotes, Images and Tweets, and can also be shared on Facebook, Twitter and MySpace. You can either share the entire page of results, or one specific item from the list.

what is semantic search

Signing up for an account gives you the added benefit of following specific information streams on certain results. However, not all search results can be followed. So while searching for "Barack Obama" can result in a stream that can be followed, searching for "Obama" alone does not give users the same option.

Additional information about each search term will also be displayed on the page, but again, this is limited to certain results. Using the example of Barack Obama, additional information includes links to other world leaders, an excerpt from Wikipedia, and product results from Amazon.

what is semantic search

If you don't want to sign up for a new account, you can connect your Google, Twitter, Yahoo, Facebook, Windows Live or Blogger accounts in order to sign in.

Like DuckDuckGo, Evri has its own disambiguation results, in a sidebar, giving you the chance to choose a more specific and relevant term.

Evri has a toolbar which supports Firefox and Internet Explorer, allowing you to easily search for and share content. They also provide users with a slick, free iPhone app [iTunes link] which is divided into 3 main tabs - Recent popular news, a search tab, and collected items. Searching for any given term will result in the option to view recent news, images, a profile page, and related items.

It should be mentioned that if you want to use the follow feature on the iPhone app, you will have to create a new Evri account, as connecting to one of your existing accounts will not suffice.

Evri recently joined forces with Twine, so it will be interesting to see how these two services are brought together, in an attempt to provide even more relevant results.

Truevert

Truevert presents an interesting twist on the semantic search engine, labelling itself as a 'green search engine.'

All results are filtered and organized from one specific perspective - with the topic of environmental awareness in mind. Searching for any term will be put in the context of environmental concerns, so for example, searching for 'meat,' - the first page of results consists of meat in relation to climate change, organic options, and sustainable food.

Truevert's front page features the latest news from popular environmental websites and blogs.

If you're interested in semantic search engines, you should also take a look at Stefan's article about Juice, a Firefox addon whose results are also based entirely on semantics.

Have you tried out a semantic search engine as an alternative to Google? Let us know what you thought of it in the comments.

Image credit: Chris Chidsey