One of the most powerful aspects of the Web is linking – the ability for one page to refer to another page, creating a chain of references that allows the reader to delve into more detail or into related subject material when reading a given article. Like any tool, however, linking can be used well or used poorly.
I was prompted to write this article after recently spending quite a bit of time fixing (generally by deleting) broken links in a web site I inherited. This exercise made me realize that there is a wide range of opinions among Web authors about what constitutes a good link, and what constitutes good linking practice.
In this article we will review some thoughts on what makes links useful or harmful to an article on the Web, and suggest some general practices to improve the quality of links and to reduce the future maintenance costs of keeping links in a page working.
These are only guidelines, of course. Every suggestion here has valid exceptions, but hopefully the guidelines will still serve to improve the quality of Web-published articles and to make it easier to keep web sites up to date and relevant.
It would be easy for a webmaster to say "don't put links in your articles – it's too hard to maintain." But that would be poor advice; there are many excellent reasons to link from your article to other pages on the Web.
Links enhance the credibility of your article, by providing pointers to authoritative reference material (much as references do in traditional written works).
Links add value to your article by taking the reader to relevant reference or background material, while keeping it from cluttering your article with a level of detail beyond what you wanted to cover.
Links may even introduce your reader to separate, but related, topics and promote whole new avenues of exploration for them.
Links are a way of "voting" for interesting pages. Some search engines, such as Google, rank pages by considering how many other pages link to them, so a link to another page is a "vote of confidence" in the information it contains.
Why Not Link?
Despite the value of linking, excessive, unnecessary, or poorly-chosen links can severely reduce the perceived quality of a web page. There are several potential problems with links.
Links can become out of date. A broken link is annoying, and a sign of inattention. Readers and webmasters hate them, and you should too. Worse, the link might work but lead to a page that no longer contains the information you were referring to. Your readers will wonder what on earth you were thinking.
Inappropriate, unnecessary, or silly links may annoy your reader. A reader follows a link expecting it to enhance their experience. If it is broken or pointless, they will be annoyed with you and probably won't continue through the information you have published.
Links might distract your reader. If they follow a link, how do you know they'll come back? If the page you send them to is more interesting than your own page, you've lost them.
Links imply a relationship between pages, or between the opinions of their authors. Although a page you link to may contain local relevant information, you are implying a broader relationship: that you agree with, or recommend, the general point of view of the overall site to which you are linking. This may not be the message you intended to send.
Dynamic links may involve your reader in unwanted services (e.g. a link to a book store that leaves them in a half-completed purchase page; possibly with personal information already filled in by their over-helpful browser.) This is considered rude by most people, and even fraudulent by some.
Why Do Links Break?
Why would a link become out of date anyway? If it seemed appropriate when you wrote the article, why would it be inappropriate, or not work at all, a year later? There are several reasons why links become invalid.
The target site may be reorganized. If their page structure or folder structure changes and you are linking to an internal page, the link will no longer work.
The target author may delete or change a page they no longer consider relevant. Unless you have made other arrangements, they are under no obligation to keep a page online and to keep its content constant just because some stranger is linking to it. In fact, it may be that the page you linked to was never intended to be permanent or constant. For example, you should not expect a page with the file name "this_weeks_news" to have the same content a year from now that it had when you decided to link to it.
The domain name to which you link may be changed. There are many reasons why this happens. A personal page associated with an individual will likely change domains if they move or subscribe to a different Internet Service Provider. A page associated with an organization may change domains if the company is acquired, goes out of business, or changes their brand name.
To use links well, making them a positive experience for your reader and enhancing your own credibility as an author, I suggest you follow the following guidelines (with, of course, exceptions when appropriate).
Link When Appropriate
Use a link when it is relevant and adds value to the article you are writing. For example, if you are writing about planets, and you write the sentence
"The Cassini spacecraft has measured Saturn's powerful magnetic field."
it would be quite appropriate to provide a link from "Cassini spacecraft" to more information on that mission (probably into NASA's site), or from the phrase "Magnetic Field" to some kind of article discussing that phenomenon. However, linking the word "the" to a dictionary defining the word, or to a discussion of the appropriate use of prepositions in the English language, would be irrelevant and annoying. Don't link to prove that you know how to do it; link to add value to your topic.
|Good:||"The Cassini spacecraft has measured Saturn's powerful magnetic field."|
|Bad:||"The Cassini spacecraft has measured Saturn's powerful magnetic field."(Yes, this example is rather silly; but I have seen each of these types of bad link choices, separately, in real web pages.)|
Use an Appropriate Link
Once you have decided to link from your own article to another, take the time to select an appropriate link. Link to your own site or articles if possible. This keeps all the style, structure, and maintenance requirements consistent.
Link to definitive references or public authorities if they are available and appropriate. In the example above, to link to information on Magnetic Fields, you would be better linking to Wikipedia's article on that topic than to a student's essay found on their personal home page with Google. You don't know if that student's essay is correct information (maybe that failed that course), or how long that page will be there.
By all means link to personal pages if they are appropriate to the point you are trying to make, but understand you have an obligation to believe the information to which you are leading your reader is appropriate. Is it accurate? Is it in a style and at a level of detail that is appropriate for a reader who follows your link?
Be careful what you're associating your article with. If you are writing a scientifically accurate astronomy article on The Moon, for example, you should think carefully about linking to "Moon Landing Hoax" pages, or Astrology pages, just because they happen to contain a convenient definition or an image you like. You may be leading your reader astray. On the other hand, if you intended to introduce your reader to the world of fringe science, conspiracy theory, superstition, and so on, then such a link would be completely appropriate.
Don't trick your reader. For example, if you refer to a certain book, by all means provide a link to the author or publisher, or even a book store. But don't make the link part of an affiliate program that will earn you a commission unless that type of behaviour is appropriate for the site. (For the RASC site, it is notappropriate.) You will lose credibility if the reader believes your article was only thinly-disguised advertising to earn you revenue. And in articles published on web sites associated with organizations, such references may actually be perceived as a conflict of interest.
Link to Last
If you are writing for a time-limited publication such as a "news of the week" page, time-sensitive information is a safe target for your linking. However, if you are writing an article that will be available for a long time, remember that someone may try to follow your link many years from now. Will that link still be there, and will it still generate the results you wanted?
To improve the chances that your links will last, follow some simple "do"s and "don't"s.
Prefer linking to pages designed to be permanent or likely to remain stable. For example, the Wikipedia pages use a simple naming convention designed to remain stable for long periods, and are generally considered safe long-term links.
Before you link to a page located deep inside another site, look at the site structure in the target URL. If the structure is complex, or implies that it may be temporary, time-sensitive, or unstable, it would be safer to link to the top-level domain only, using a sentence to tell the reader to search for the necessary information.
For example, it would probably be unsafe to link to a site whose file name path is "http://www.somesite.com/thursday/temp_while_reorganizing/page.html". If this is truly the best page to which to link, it would be safer to link to "www.somesite.com" and instruct the reader to look for the page of interest. If you feel you must link deep within the site, write yourself a reminder to frequently check if the link still works, and have your page updated as necessary.
Don't link to pages that are obviously time-varying, except in a time-sensitive article such as a review or a blog entry. A page called "this_weeks_news.html" may contain something that interests you now, but the name implies that it will contain something different when your reader follows a link to that page years from now.
Don't link to dynamically-generated pages (e.g. pages whose addresses include references to a "cgi-bin" directory, or which end in ".asp" or ".jsp"). While this is sometimes unavoidable, it generally suggests your are accessing information that the owner considers highly dynamic (e.g. a product catalog). If you link to that address, you are taking two risks: that the information is still there in the future, and that the owner doesn't make changes to their software that would render your archived link invalid.
Don't link to ftp sites or other file repositories; just web pages. Authors expect others to link to their web pages and will keep them somewhat stable, but generally consider their file repositories their own to reorganize at will.
When you want to refer to the work of others, linking is a better approach than copying their work into your site. However, you should still respect certain conventions.
Generally you can assume you have permission to link to another web page found openly on the Internet. However, you should not assume you have permission to imbed images or other content from someone's page into your own. The author intended their work to be seen in their context, not yours. If you want to use only a portion of the content of someone else's page (e.g. imbedding an image), write to that author and ask permission. Then, if you receive permission, include an appropriate note attributing the image to the original author and thanking them.
Never publish a link into an area whose owner seems to consider it private.
Never publish personal information (e.g. phone number, email, address) about someone else on a web page without their permission; and when you publish someone's email address, help them avoid SPAM by using one of the available techniques to make it harder for SPAM-harvesting robots to pick up their email addresses. (e.g. on the RASC site we use various HTML codes so that, internally on the page, email addresses are not stored in the easily-recognizable standard format).
If you write an article that is published in some long-term area on the web (such as our AstroNotes archive), revisit every year or so and check that the links still work. If they don't, inform your webmaster. If you can find an appropriate replacement for the broken link, let the webmaster know.
Your webmaster will likely delete broken links after a while, but you shouldn't expect them to find new ones for you – it's your article, after all.
Finally, link using an appropriate writing style. Remember that the objective of Web links is to allow you to refer to related information in a way that flows naturally.
Therefore, it is generally considered poor style to write about the link. Put the link on a phrase you would have written anyway – don't make the link the subject of your sentence with phrases such as "click here for. . .".
Especially, don't put the URL in the text – that's not useful, it's ugly, and it will usually destroy the typesetting of your paragraph (since URLs are long and have no natural break points); the point of Web links is to shield your readers from that ugly coding.
|Good:||"The Cassini spacecraft has measured Saturn's powerful magnetic field."|
|Inelegant:||The Cassini spacecraft has measured Saturn's powerful magnetic field. Click here to learn about the spacecraft, and click here to learn about magnetic fields.|
|Downright Ugly:||The Cassini spacecraft has measured Saturn's powerful magnetic field. This link has more information about Cassini: http://saturn.jpl.nasa.gov/spacecraft/. There is information about magnetic fields at http://en.wikipedia.org/wiki/Magnetic_field.|
Note that this advice against putting the linked address in the text applies to email too. For example,
|Good:||For more information email the webmaster.|
|Redundant:||For more information email the webmaster at firstname.lastname@example.org.|
All of the comments above are personal opinion and general conventions drawn from experience in writing and reading good web articles. Feel free to pick and choose the guidelines that meet your needs. We hope they will help your writing to become more valued and longer-lasting.