True Knowledge - Blog

Going to LeWeb'09 Conference

Next week is the LeWeb'09 conference in Paris, and our CEO, William Tunstall-Pedoe, and Commercial Director, Mitch Pender, will be there!

Come up and have a chat at our stand in the Demo Zone where they'll be showing you the latest and greatest at True Knowledge.

Wondering When

As 2009 draws to a close, it seems a lot of people are asking True Knowledge when events have happened, and are looking to the future asking when some events will happen.

It all started with when do the clocks change a few weeks ago, but already some people are asking about the start of British summer time!

Of course Christmas is on people's minds and so we're seeing people wonder How long is it until Christmas? and asking which day of the week it will be. We're also helping people buy a christmas tree and the christmas tree decorations, and also a tree stand if they want one.

People are also keen to start planning 2010. We're seeing people ask about Easter in 2010, Good Friday, and the ever-important Easter Monday holiday.

Speaking of holidays, people are wondering when is Presidents day in 2010, the May bank holiday (known as Whitsun or Whit Monday) and even Thanksgiving in 2010! We've barely had the US 2009 Thanksgiving and our users are already keen on the next one.

Underlying Technology

The answers to the examples above hide quite a bit of cleverness our knowledge engine does. For example, Christmas is always on the 25th of December, and so asking When is Christmas? returns just the date without a year. However, asking When is Christmas in 2010? will give the full date including the year.

Other types of holidays are not fixed but fall on different days each year; Easter for example. Our knowledge engine recognizes this situation and thus asking When is Easter? will always return an answer with a full date that includes the year.

Yet another type of time-related question is completely dynamic questions, such as asking How long is it until Christmas? The answer to this question changes every second as we approach the actual day. Currently we return a nicely-formatted answer in years, months, and days as the answer warrants.

A nice variation is mapping dates back to holidays. Because True Knowledge has extensive knowledge about holidays around the world, we can answer questions about specific dates in a given geography. For example, Was January 2nd 2009 a holiday in Scotland?

Finally, there is another type of time-related questions we can answer: which day of the week a given date was, for example What day of the week was 25/1/77? Yes some people can mentally work the answer, but for the rest of us, True Knowledge can help.

Of course you can try these by asking us or querying our API time-related questions.

Calling the True Knowledge API using Javascript

A very common question we receive from our API users is how to call the True Knowledge API using Javascript/AJAX.

The short answer: you don't call the API directly using Javascript, but you can call it indirectly. This post explains why and how to do so.

Why not

The reason for not calling the API directly is because the URL call contains your API account credentials, namely your username and API "password" (the API key if you will). If you embed this information into a web page so that it can call the API directly using Javascript, you will be exposing these credentials: anyone can then find your account details.

Another complication: our API currently outputs only XML, which is not the most Javascript-friendly output.

Solution

So what to do? Proxy the calls via a server-side script on your website. The server-side script, would be written in PHP or Python or your programming language of choice. It will accept, via a query string variable, the actual search, process it, and then return the results to the Javascript.

In detail:

• Create the server side-script; let's call this script tk.php and let's say it is hosted on your website at http://example.com/tk.php. We'll talk about the exact contents of tk.php in a second.
• Using jQuery or any other way to do the AJAX call, request tk.php. For example, if the Javascript wants to call the True Knowledge API to ask "what is the capital of France", the AJAX call could be to:

  http://example.com/tk.php?input=what+is+the+capital+of+france

  Here, we're using the query string variable "input" to pass the search to tk.php
• Wait for tk.php to call the True Knowledge API and display its output in the page. The exact details of this vary by how you are doing the AJAX call, and most Javascript frameworks like jQuery and Prototype give you an easy way to embed AJAX output into a web page.

What happens on the server

We already have an excellent starting point for tk.php: it is the da.php example in our API PHP library. What we want here is an even simpler version of this file, so we're going to strip it down.

The da.php file calls our Direct Answer API service, which is the easiest to work with for this example. You can certainly build more complicated API calls using a True Knowledge Query API call as detailed in the tkquery.php file in the library examples folder.

The first task is to get rid of the HTML page formatting because the output is going to be embedded into a pre-existing HTML page.

Secondly, you need to decide if you would like the AJAX output to (potentially) show any errors. In the code below, I've commented out anything that does not display a search result.

You'll notice that the code below is printing everything the API returned without any real formatting and basic HTML markup. Of course customize this to your needs.

And with all this said, below is the full code for the tk.php proxy for your AJAX calls.

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<?php define('API_DIRECTORY', dirname(__FILE__) . '/..'); define('API_ACCOUNT_ID', ''); define('API_ACCOUNT_PW', ''); if(isset($_GET['input'])) { //You should sanitize the input as necessary for your application. $query = $_GET['input']; } if(is_string($query) && strlen($query) > 0) { require_once(API_DIRECTORY.'/api.php'); $request = new KnowledgeEngineDirectAnswerRequest(); $request->setAccountId(API_ACCOUNT_ID); $request->setAccountPassword(API_ACCOUNT_PW); try { $request->setQuery($query); $response = $request->execute(); if(strlen($response->getErrorCode()) > 0) { //NOTE: for this example, we are hiding any errors //echo "<p>Error for query (".$query."):</p>"; //echo "<p>".$response->getErrorCode()." ".$response->getErrorMessage()."</p>"; } else { echo "<p>Answer for ".$query."</p>"; echo "<p>".$response->getTextResult()."</p><hr/>"; if ($results = $response->getResults()) { foreach($results as $result) { echo "<p>True Knowledge ID: ".$result->getId()."</p>"; if($result->getOfficialWebSite()) { echo "<p>Official website: <a href=\"".$result->getOfficialWebSite()."\">".$result->getOfficialWebSite()."</a></p>"; } if($result->getWikiPage()) { echo "<p>Wikipedia page: <a href=\"".$result->getWikiPage()."\">".$result->getWikiPage()."</a></p>"; } if($result->getImage()) { echo "<p>Image: <img src=\"".$result->getImage()."\" /></p>"; } echo "<hr/>"; } } } } catch ( Exception $ex) { //NOTE: for this example, we are hiding any errors //echo $ex->getMessage(); } }

True Knowledge Partners with Omgili

We are really pleased to let everyone know about another exciting True Knowledge API partner, Omgili.

Omgili, a VC backed search start-up that focuses on “many to many” user generated content platforms, such as forums, discussion groups, answer boards and other sources, has integrated True Knowledge results into their Google@Omgili service. It is a fantastic example of how True Knowledge can be combined with other search methods to help provide a truly superior search experience, as shown in the example search for "president of france in 2009" screenshot below.

Google@Omgili brings together knowledge-based responses powered by True Knowledge and Google search results and it combines theses with their ability to find forum discussions about the results Google returns. With this combination, you can get direct answers to your questions, and you can find people interested in the same topics as you as well as finding more in depth discussions about the subject you are researching.

Organizing the World's Knowledge: The True Knowledge Ontology - Part I

At the heart of the True Knowledge semantic technology is our ontology. Our ontology describes a tree-like structure of classes, and every entity fits into this tree.

In this post I'm going to explain a bit more about how we structure the world's information and how you can tap into this structure using our API.

But first, some theory. Don't skip it because it directly affects how you query the True Knowledge API!

What is a Class?

The easiest way to explain a class is take a real world example. Below is an image showing the class [book].

In our ontology, the class called [book] describes all books. It is the collection of all books that we know about, and it will be the home of all books we don't know about when they are added. All books have similar properties and attributes, and all of them can be described in similar terms: If I ask you to imagine what a book is, your mind will picture something similar to what other people imagine a book to be. In short, if you can say "This is a <something>", that something is a class.

We know there are different types of books, like novels, cookbooks, art books, textbooks, science books, science fiction books, etc. These are all subclasses of the class [book]. A subclass is a more specific class, and so is lower down in the ontology tree.

Of course it works the other way too: a more general class is a parent class. So the parent class of [science book] and [cookbook] is [book]. The class [book] itself has two parent classes, [written publication] and [source of knowledge]. The class [written publication] has other subclasses such as [comic], [issue of a periodical], etc.

You can easily browse our ontology by looking at the profiles of a class and clicking through to parents and children. Here are profiles for some of the classes mentioned above:

• [book]
• [written publication]
• [comic]

Instances of Classes

So far we've been talking about classes which are collections ordered in the ontology tree. So what about members of these classes? How does True Knowledge handle specific books like The Da Vinci Code?

Each member of a class, for example each book, is an instance of that class. So [the da vinci code] is an instance of [book]. Likewise, [dune] is also an instance of [book].

API Queries

To test these queries, you will need to use our API library. Details of our new API library are in this previous blog post.

You can get all subclasses of books that we know about with this query:

query bookclass
bookclass [is a subclass of] [book]

The following TK Query gets a list of novels from True Knowledge:

query novel
novel [is an instance of] [novel]

The query asks for a variable called "novel" which satisfies the relation "[is an instance of]" for the True Knowledge ID of the class [novel].

Finally, you can tap into the power of having a structured ontology tree by getting a list of books, novels and everything else, with this query:

query book
book [is an instance of] [book]

If you look through the list of results returned by the books query and compare it to the novels query results, you'll see overlap. This is because all instances of the class [novel] are also instances of the class [book] because [novel] is a subclass of [book]. You can go up the tree more and ask for all instances of the class [written publication], which will get you all books (including novels) and other publications.