Popups: What are they good for?

This is the second article in a series on web usability and accessibility. In the first article I talked about one of my top web annoyances: opening links in new browser windows. Popups are very similar in nature but can sometimes serve a useful purpose.

By my definition a popup is a small window which is used to supplement the content of the main browser window. Therefore it's always displayed at a considerable smaller size than the parent window. In most cases popups only have a title bar and no location bar or navigation buttons.

What I don't consider to be popups are windows which contain a full website and are only opened to have it displayed at a certain width and height, without any buttons, without a location bar because it's hosted on a different domain, etc. As far as I'm concerned those are all different versions of a 'new browser window'. If you read my first article you know the reasons why this is a bad idea.

The rise and fall of popups

As far as I can tell popups where made possible when Javascript was first introduced in Netscape Navigator 2. The Javascript programming language can be used to generate new windows without user intervention in different sizes, without browser buttons etc.

It didn't take very long for online advertising companies to use popups as a new means to get the users attention. Up until then banner ads where the main form of online advertising.
Since then popups have been abused so much and users got so annoyed by them that all modern web browsers support some form of popup blocking.

Popup blockers try to prevent any new windows from opening automatically and only allow popups when a user performs some action (clicking a link for instance). This doesn't mean advertising companies have stopped using them or didn't try to circumvent them but it has made them a lot less effective as a marketing tool. Coupled to that the very succesful and effective text based ads (like Google AdSense) leads me to believe popup adverts will become less and less frequent in online advertising.

Is there any use for popups?

Although it wouldn't seem that way I can think of two possible uses for popups:

Problems using popups

There are certain limitations which you should be aware of when trying to implement popups into your website.

Javascript must be enabled

It's not possible to generate popups without the help of Javascript code. If a user doesn't have Javascript enabled, either through corporate policy or lack of browser support, a site might break. This is especially true for users with disabilities who often browse the web with text based browsers. Text based browsers rarely support Javascript. Checkpoint 6.3 from the Web Content Accessibility Guidelines has this to say about scripts:

"Ensure that pages are usable when scripts, applets, or other programmatic objects are turned off or not supported. If this is not possible, provide equivalent information on an alternative accessible page."

This makes it impossible to implement modal dialogues in any meaningful way because these always rely on Javascript. Contextual help could be done by linking to the help text on a different page when Javascript isn't available.

Not letting users know what's going to happen

If your somewhere in the middle of a web shop checkout what will happen when you click a help link? Will it open in a new window, in a popup or replace my current page? It's crucial to inform the user of what's going to happen so they don't have to worry about loosing anything they have done up until that point. Checkpoint 10.1 from the Web Content Accessibility Guidelines describes:

"Until user agents allow users to turn off spawned windows, do not cause pop-ups or other windows to appear and do not change the current window without informing the user."

Popup blockers can block your popups

This seems pretty obvious but there's no guarantee that a popup blocker won't block the popup. If you want to be a 100% sure this doesn't happen you shouldn't use popups.
Also don't ask users to enable popups for your website because there's absolutely no guarantee they will or are even able to.

Users don't like popups

And that's putting it mildly. Because popups have mainly been used for advertising most people have a tendency to close popups as soon as they appear.

Popups must be distinguishable from the main browser window

As I wrote at the beginning of this article popups should supplement the content of the main browser window. Else your just opening new browser windows and those have a lot of usability problems as well.

My advice

Popups have a useful but limited purpose. When used correctly there's no reason not to use them however it's a lot of work to make an accessible website which relies on popups. In those situations I would try to avoid using them alltogether.

Categorie├źn: usability accessibility