Flash Usability
By: Tom Wheeler - Software Engineer
Macromedia's Flash product promises to make the Web more interactive and more exciting. In fact, the product description on Macromedia's site says:
Macromedia Flash is the key to designing and delivering low-bandwidth animations, presentations, and Web sites. It offers scripting capabilities and server-side connectivity for creating engaging applications, Web interfaces, and training courses. Once you've created your content, 96% of the online audience will be able to view it with the Macromedia Flash Player.
Macromedia describes its Flash product as a tool that can help with creating "engaging applications" and "low-bandwidth" animations, which you can use to "create the ultimate user experience". As with any tool, there are advantages and disadvantages:
It's important to design your Web site with your user's needs in mind because no matter how your site tries to create revenue -- whether through online sales or advertising -- it can't succeed without users. And since there are millions of Web sites out there, users won't come back to ones that they find hard to use.
So let's define usability. I like the definition that StudioWorks has in their Usability vs. Interactivity
article:
The ease at which a user can locate the relevant information for which they are searching.
That's important, because numerous studies have shown that people on the Web use it to seek information and rate ease of use more important than nearly any other factor.
Advantages:
Vector graphics are flexible
Flash produces vector graphics that, unlike raster graphics formats such as GIF, JPEG or PNG, can be resized without adversely affecting picture quality.
Vector graphics are also very small in file size and are therefore quick to download.
Little or no programming knowledge is necessary to use Flash
Compared to Java Applets, it's easy for non-technical users to create Flash movies.
Flash's SWF file format is fairly open standard
It's possible to create Flash movies without even using Flash. You can use products such as Adobe's LiveMotion and even some Web-based tools to create Flash movies.
Widespread acceptance and adoption of Flash Player
Macromedia's site boasts that 96% of Web users can view Flash movies without having to download a plugin. Flash movies can be viewed in both Netscape Navigator and Internet Explorer. In addition to being somewhat browser-independent, it attempts to be platform- independent. Macromedia also produces Flash players for Windows, Mac, Linux and Sun's Solaris version of UNIX.
Cross-platform development environment
Macromedia Flash (which you need to create movies) is available for Macintosh and 32-bit Windows PCs.
Allows for user interactivity
A user can interact with a Flash movie, for example, to play games. This kind of interactivity is not possible with animated GIF or PNG images.
Reusable Objects
The Flash development environment promotes designing movies as a collection of reusable "objects." This results in smaller download sizes and reduced development times.
Disadvantages:
Flash suffers from some usability problems. I'll talk about some of the major ones now and then present solutions for overcoming many of them.
Long download times
Despite lightweight vector animations, Flash movies can take longer to download than most users want to wait. When you begin to add the really flashy elements to your movie -- things like video and sound -- you can easily bog things down. Though broadband Internet access has become more prevalent in the past two years, most home users (and many small business users) still access the Web over a modem.
Flash can destroy normal user navigation
Sites which are done entirely in Flash are a usability nightmare. Web users are accustomed to certain navigation controls such as the back and forward buttons. Unfortunately, in multi-page Flash sites, the back button doesn't take you to the previous page -- it takes you to the previous site.
Since Flash sites are often used as "brochureware" to present product information, this can be really annoying, since you cannot easily use back and forward to compare two similar products on the same site.
Developers will often try to overcome this problem by designing some navigation features into the Flash movie, but this often exacerbates the problem since the user is forced to learn some new, nonstandard navigation scheme.
Finally, many Flash sites "pop up" in a new window. For some reason, developers often feel compelled to remove the address bar, navigation bar and status bars of these new windows, which make it difficult for a user to know what's happening.
Flash lends itself to self-serving sites and design excess
As I stated before, Web users tend to seek specific information. They also tend to disfavorably view most things which get in the way of seeking that information. Many sites have often long and useless "Intro" sites which don't serve any need of the user.
It's hard to print text rendered in Flash
Since Web pages can change dynamically, it's often necessary to print them out and capture a "snapshot" in time.
This is particularly important in Flash sites that present product information, since the user may need to print hard copies of features and present them to someone else for approval.
When a user uses the browser's print button to print the text rendered in a Flash movie, the text will usually come out very faint, dithered or blurry.
Stale Content
While Macromedia says that one of Flash's goals is to retain visitors, countless studies have show that users use the Web to seek information and prefer sites that are updated frequently.
Since creating content with Flash is typically more labor-intensive than creating similar content with HTML, Flash content tends to be changed less frequently.
It's not always possible to select, copy and paste text rendered in Flash
To add insult to injury, you can't select and copy text from a Flash movie and paste it into a word processor to prepare a report.
Update: With Flash 5 you can now select a text box, then check the "selectable" checkbox in the text options panel. Users should then be able to select that text. Thanks to Olivia Kobelt, Web designer/developer at The Principia for pointing this out.
Lack of User Control
I'm probably in the minority, but before I click links on a site, I point to them with my mouse and look in the status bar to see where the link will take me.
You also cannot use the browser's "Find" feature to find specific text on a page.
Lack of search engine support
Most search engines cannot index Flash content, and users will be less likely to find a Flash-heavy Web site through a search engine.
Accessibility Problems
Flash doesn't allow (AFAIK) the user to resize fonts in order to make them larger or smaller (as one might do with the font button or preferences in IE or Netscape). Designers often make fonts too small to be read by people with smaller monitors, lower resolution or poorer eyesight.
It also appears that Flash content cannot be accessed by screen readers and therefore is unavailable to user's with poor or no eyesight.
Though Flash player software is free, you can't assume that users have it or want to install it. They might also not have the correct version. Like many software applications, content created in a new version of Flash might not be viewable with older versions of the Flash player. Even though the Flash player is free, some users don't have the technical ability to install plugins (think about your mother or grandmother). Other users (such as corporate users) may have the know-how but lack the permission to do so. As with HTML, it's a good approach to write to the lowest common denominator unless you have a good reason not to do so.
I have outlined some of the problems with Flash. I will now share some advice for how to overcome them:
Accessibility
You can use sound on mouseovers to describe an object. This could help with screen readers and designing a site for accessibility. It can also make the download too large, so use it sparingly.
Printing
At least with the Windows NT version Flash Player 5 using Internet Explorer 5.01, you can right click on a Flash movie and print from the context menu. That's not obvious too most users, so you might consider adding instructions to your sites help pages, or at least a visual cue of how to do this.
Font resizing
You can, "zoom in" on a specific Flash movie to see it better. Unfortunately, this doesn't stay locked; you have to keep doing it for each Flash movie on each page.
Skip Intro
Most Web users are looking for information and splash pages don't provide much. They merely serve as a roadblock to your users' needs, so avoid them where possible. If you must have one, use cookies or session management to skip past it after the user has already seen it (like www.sgi.com) and always give the user an option to "skip intro".
Avoid unnecessary elements
Too many elements on a page compete for a user's attention, particularly when they are animated. Use whitespace to guide a user's eyes to what they want to see.
Don't reinvent the wheel
Look at the most popular sites on the Web. Your users have probably seen those sites too, and will likely find good navigational ideas borrowed from those sites to be intuitive. There's usually no reason to make users learn a new navigation scheme.
Provide context in navigation
The user should be able, at a minimum, to tell where she is, how she got there and what other choices are available. You should also have some way to let them go "back" and "forward", preferably with the standard browser buttons.
Pop-up windows are hard to manage
And since desperate advertisers are starting to use them, users might close them before they load fully, having though that it was just another ad. If you do open a new window, it's preferable to leave the standard navigation and status bar visible.
It's also a good idea to put some sort of icon or cue to any link that will spawn a new window.
Be consistent
Make all the pages on the site look as if they belong together. It's clever design to use a different, yet compatible, color scheme for different sections of your site, but don't move the navigation bar around to different parts of the page.
Don't overuse sound
For most sites, sound can enhance the user experience but should not dominate it. After all, not all users have speakers and some that do have them turned off. Make sure that you can navigate your site even without sound. Also, sound files can really increase the download time for your pages.
Quick Downloads = happy users
Low bandwidth connections still dominate the market for home users. No one likes to wait for sites to load, so try and keep your pages to 40KB or less and put warnings near links that point to heavy pages. Provide alternative HTML content where you can and give the user the choice about which he rather view. Finally, try and hit your pages over a 28.8 modem and reduce download sizes where necessary.
Do usability testing
This can range from formal professional testing labs to informal testing on a few coworkers. Just be sure that you can get honest feedback. You should list your site's main objectives and see if users can accomplish those tasks easily. Redesign or tweak if necessary.
Update your site's help pages
It's not obvious to most users that they can print content by right-clicking the Flash movie and choosing print from the menu. You can use your site's help pages or FAQs to teach them how to better use your site.
Use HTML and Flash to complement each other
Creating an entire page or site in Flash will cause trouble for your users and limit your ranking in search engines, but you can use Flash effectively if you make individual elements with Flash and place them on an HTML page in concert with text and other graphic elements. Be sure to use ALT tags! You should also use <noscript> tags to provide alternate content. Finally, use meta tags to make it easier for some search engines to rank your content.
Reference:
Player Platforms and System Requirements
According to Macromedia:
The Flash Player is available for 32-bit Windows operating systems like Windows 95/98, ME, NT, and 2000, Macintosh, as well as Sun's Solaris version of UNIX and the popular Linux operating system.
It's peculiar to note that the system requirements for the Macintosh seem to specify that you must have the older "68K" architecture. These computers haven't been manufactured since 1994, as they were superseded by the PowerPC chip found in all newer Macs. Still, I have successfully used the Flash Player plugin under both Netscape Communicator and Microsoft Internet Explorer on recent PowerPC Macs. I conclude that this must be a mistake.
I have also used the Sun Solaris version and the Linux version. While Macromedia does claim that they are production quality releases, I found both to be unusable. The Linux version would not play any sound, and both versions skipped nearly half the frames. I also found that in some cases, links didn't work properly, at least on the Linux version.