Usability For The Web On Television
Posted on 22 Jan 2001
by frank gaine (gainef)
Rated 3.96 (Ratings: 9)
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Usability for the Web on Television
The convergence of the web and television throws up numerous challenges for usability engineers. As more and more of the population choose to access the Internet through their television (usually via set-top boxes and with the assistance of television remote controls), optimizing web pages for use on these devices becomes a priority.These issues tend to be exacerbated by inherent differences between the two technologies. For instance, television is usually thought of as "lean-back" technology, whereas the computer is seen as "lean-forward" technology. Television viewers on average sit more than 9 feet away from their sets, whereas computer users are usually within 13 inches of their monitors. Television viewers are accustomed to being passive and having information presented to them. Computer use requires more active interaction and maximizes user initiative.
It is possible that the fundamental conflict between these modes of operation will mean that web-on-television is doomed to failure. But, in the meantime, what can be done to ensure high quality user-experience when viewing the web on TV?
Page SizeUnderstand the size of the screen on which your page will be displayed. Systems in North America and Japan, based on Microsoft's WebTV, display Web pages in a fixed 544 x 372 screen space. Pages that are wider than 544 pixels will be scaled to fit that width. Conversely, pages that fall short of the regulatory 544 pixels will be displayed within a sea of wasted white space. Within the 544-pixel-wide screen environment, designers are limited to a two column layout when opting for a columnar page format.The 544-pixel benchmark is a helpful guideline for designers and usability engineers alike, but it does not incorporate the ever-increasing spectrum of screen sizes that continue to emerge onto the market. With this in mind designers should consider?
There is no way (yet) of knowing just how large a screen your users have, so you ought to design for all screen resolutions. To master resolution-independent design, never use a fixed pixel-width for any tables, frames or other design elements. Instead, use percentages of available space, as opposed to fixed sizes. This way, your code can adjust itself to whichever screen size accordingly.
TextThe default text size for the web on television is 18 point (as opposed to 12 point for computer-oriented browsers). Due to larger font size and smaller screen resolution, less text may fit onto a television viewing area than on a computer monitor screen. With this in mind, it is essential to be as concise as possible when creating content for the Web on television. Keep it simple; having minimal and easily assimilated content on each page is the key.In an ideal world, it is best not to include text within images, as the characters can prove difficult to read on a Web television screen. If needs be, text represented through graphics should be kept over 16 points in size to ensure legibility. This is important in the context of navigational buttons. Legibility is also enhanced, as always, by bold text and high contrast between text and background colour.
ColoursTelevision screen displays are not as sharp as those of computer monitors. Use shape as well as colour to get your message across. Common and unavoidable variations between television displays may mean that subtle colours will not achieve their desired effect. Colours can also appear more vivid on television than on computer screens and should be de-saturated if possible.
When a set-top box is used in accessing your web page on television, it should not be forgotten that such a box has less memory than a personal computer. It will better handle Web content if the pages are small and do not take up a significant amount of memory. By keeping file sizes small, download times are kept to a minimum.There is no need to eat up precious memory by integrating the latest technology into websites that few will have immediate access to anyway. Use the time and tow the line. People like fast service and usability engineers ought to bear in mind that every five bytes of memory saved shaves a valuable millisecond off download time. TV users, in particular, are used to the instantaneous reaction of the remote control and are unlikely to tolerate not getting to their destination as quickly as possible.
Ideally, the page should be clear and easy to navigate using the relevant input device (usually a television remote control and wireless keyboard which are suited for small amounts of user input). Excessive scrolling or an irrational order in reading links will only serve to confuse and frustrate the user. Avoid excessively long lists of links and provide rich hypertext.
As always, it is imperative to test your pages with representatives of your target audience on real web television systems. Guidelines are useful, but only your target audience can really judge how successful your offering is.