Welcome to the References Tour
Welcome to Wikidata! In this tour, you’ll learn how to add references. Adding references ensures Wikidata has high quality data. A reference (or source) describes the origin of a statement in Wikidata. We will learn about some of the important principles and policies of Wikidata along the way.
If there are any terms in this tour you would like a definition for please see the Glossary.
Please note that the page in the background is only a replica of a real page, you can think of it as a sandbox for you to play in and try new things. Your changes won't appear on Wikidata so there's no need to worry while making edits in this space. Let's get started!
Why Wikidata uses references
Like in Wikipedia it is important that content can be verified by others to make sure it is correct and comes from a reliable source of information, such as a book, scientific publication, or newspaper article.
A Reference (or source) is used to point to specific sources that back up a claim in Wikidata. A reference can be a link to a URL or an item; for example, a book. Wikidata does not aim to answer the question of whether a statement is correct, but only whether the statement appears in a reference.
Reminder: An item refers to a real-world object, concept, or event that is given an identifier (an equivalent of a name) in Wikidata together with information about it.
Statements are used in Wikidata to store and represent data about an item. On this page we see a statement about the property population with a value around 7 billion. You may have also noticed a button that says [add reference] under the statement. We can use this to add a reference to show where the information came from.
Reminder A statement is a piece of data about an item, recorded on the item's page. If you'd like to learn more about statements please take the Statements Tour at Wikidata:Tours.
Wikidata has the ability to support a wide variety of perspectives about a subject.
References make it possible to record and represent multiple pieces of data on a subject, even if they contradict one another. As long as there is a reliable source for a statement it can be added to Wikidata.
Recording multiple perspectives
Wikidata has the ability to support a wide variety of perspectives about a subject, Wikidata does this by having more than one statement on the same topic. For example the item for Earth could state the global population as:
- 7 billion as of March 12, 2012 (the date according to the United States Census Bureau (Q637413)); and
- 7 billion as of October 31, 2011 (the date according to the United Nations Population Fund (Q623036))
While we know that it's not really possible for both of these dates to be correct, we can say that these values are correct according to a source of information. This is one of the ways in which Wikidata allows for a plurality of perspectives. This is also why Wikidata is known as a secondary database: it does not provide original research or pretend to have all the facts, instead it simply points to primary sources that do.
More on references
Here are some other useful things to know about references:
- References describe the origin, or source, of a statement.
- References are not always required. You don't need to include sources for values that are common knowledge, for example, that the president of a country is a human.
- References are like mini statements because they also consist of property-value pairs (more on this later).
- Sources are sometimes items on Wikidata, for example, a book like Encyclopedia of Life (Q82486) or a newspaper.
Types of reference source
There are two ways of describing a reference source used on Wikidata:
- A URL reference: a link to a web page.
- A Wikidata item reference: which uses another Wikidata item as a reference. This is usually done when the reference is a book, paper or other work which should have its own Wikidata item.
For more information see Help:Sources.
Creating a URL reference
The first kind of reference we will create is a 'URL reference'. To start to add a URL reference, click on [add reference].
We create a reference like a statement, so first we need to select the property reference URL (P854) for linking to external websites.
Add a URL
In this second box add the URL where the information comes from (in this case, the United States Census Bureau (Q637413) website):
Improving a reference
Lets improve this reference to make it more useful.
Click on the "add" button to include another part to your reference for this statement.
Reminder: Wikidata is a collaborative effort, and the more information you add about a source, the easiest it is for other Wikidata users to decide if it's a trusted source.
Publisher of URL
Start typing publisher (P123) and select it from the drop-down menu.
Publisher of URL
Now in the next field, start typing United States Census Bureau (Q637413) and click this option.
The final thing to do is to publish this information on Wikidata, to do this simply click ✓ publish.
Adding a reference from a Wikidata item
The second kind of reference uses a Wikidata item. This is usually done when the reference is a book, paper or other work which should have its own Wikidata item.
For more information see Help:Sources.
Find or create the item for the source
When the source that you would like to cite is a book, the first step is to search Wikidata to see if an item already exists. You can do this using the search bar in the top right of any Wikidata page.
If there is not yet an item for the source you'd like to reference, please create a new item for it. To do this take the Creating an Item Tour from Wikidata:Tours.
Click the "add reference" button for the second population statement now.
Start typing stated in and select it from the drop-down menu to add.
stated in (to be used in the references field to refer to the information document or database in which a claim is made; for qualifiers use P805; for the type of document in which a claim is made use P3865)
Now we need to add the Wikidata item for the source. Note this must be to a specific publication, not simply the publisher.
State of World Population 2011 (Q17518846)
The final thing to do is to publish this information on Wikidata. To do this simply click ✓ publish.
Congratulations! You've completed the References Tour.
You can now add references to Wikidata items to make them more useful for everyone.
Want to keep learning? Click here to return to the tours portal.
Still have questions? Talk to someone over live chat on IRC #wikidataconnect or check out the following pages for help: