Design Ethiopia

With the proliferation of web technologies, how do you decide which to use? When considering whether to use a particular technology, you need to ask the following questions to keep from failing your users by getting caught up in the most recent fad.

• Does this technology provide real value to the user?
• Is it cross-platform?
• Is it standard (do people need to download a plug-in?
• How much of the user’s time will be saved?
• How will users use it?
• How much learning will it require?
• What are the overall benefits to the user and provider?
• What are the development and maintenance costs?
• Will the extra complexity add significant risk to the project?

Example: Usability of Frames

Frames are sometimes used in web pages to enable convenient navigation. However, they also introduce a variety of problems, many of which have to do with how the browser supports frames.

As an example of weighing the tradeoffs in applying a certain technology, here is a list of pros and cons for frames. While our experience is that frames are most often a problem for users, consider which of these issues applies to your situation and choose accordingly.

Advantages of Using Frames
Frames can provide a technical solution that facilitates a successful user interaction. Frames can improve quality by making software development easier, primarily by facilitating the separation of content and navigation. Following are a few of the most common advantages.

Nonscrolling page components: Certain items, such as ads and navigation, can remain on the screen at all times.

Uncluttered printing: Printing is more content-specific, since usually only a single frame is printed. This can be useful, for instance, if users want to print pages from an online manual for inclusion in a preexisting document and they want the printed format to match that of the current document. The surplus navigation will not be printed.

Mandatory home page traversal: Because bookmarks only capture the URL of the frameset, you can make sure that all bookmarks will lead to your home page. This can be useful for very dynamic sites where the content changes often (no “Document Not Found” errors). It’s also useful if you want to force the user to come in through the front page (so they see current events, new postings, etc.).

Easy maintenance: Frames make it easier to change navigation, if it’s only in one frame (but if pages are dynamically generated this shouldn’t be a big deal). Other maintenance may be easier because page components can be separated.

Easier development: Frames can decrease development time because content can easily be developed independently of navigation. Checking for consistency across pages is also simplified (although frames themselves can sometimes be tricky to implement correctly).
Embedded external sites: Frames can be used to keep people from leaving your site when they click external links, by displaying external pages within a frame.

Increased speed: Pages load faster, although there isn’t a big difference as long as graphics are reused between pages of the nonframe version. The main speed advantage of frames is the reduction of screen refresh time, generally not download time.

Disadvantages of Using Frames
Despite these desirable advantages, frames create a more complicated and confusing user interface, and they introduce new design problems. The frequency with which we observe these usability problems generally leads us to avoid the use of frames.

Confused printing: The print command usually prints the most recently selected frame. In many cases this is a navigation frame, not the desired content frame, which can be extremely confusing to users.

Inefficient use of screen real estate: Frame layout is extremely difficult for small window sizes (anyone with a smaller monitor). For smaller windows, a logo, a navigation bar, and ads can use up half the window or more.

Inability to bookmark subpages: Bookmarks don’t work as users expect, so it’s not possible to bookmark a subpage within a frame. Only the home page can be bookmarked.
Confusing Back button and History behavior: The Back button in the browser does not always behave as users expect (should you return to the previous frame or the previous frameset?), and the History does not show subpages within a frame, so browsing back to previous pages is extremely confusing.

Impracticality for navbar changes: Changing the appearance of the current page in the navbars not practical with frames. This can be done by reloading the whole frameset, but this means you have less of the speed and maintenance advantage of frames.
Incompatibility with redundant text links: We generally recommend including a text version of links so that people with graphics turned off can still navigate.

If you use frames, you will need to do one of the following: only use text links for navigation (less interesting, less customizable); only use graphics links (in which case users can’t easily navigate with images turned off); include text and graphics in your navigation frame (confusing and ugly); or include text navigation at the bottom of your content frame (and thus you don’t get the ease-of-development advantage of frames).

Unpredictable search engine behavior: Sites built with frames don’t interact well with search engines, since an individual frame can be indexed as a page, so that when a user visits the page, they’re missing the other frames in the frameset (such as the navigation).
Complicated keyboard controls: Users can normally scroll through a page with the scroll buttons on the keyboard (arrows, page up/down, home/end).

With frames, this only works when the user explicitly chooses the frame first. In most cases, this is only an inconvenience. For users with motor disabilities, this can make the page significantly less accessible.

Potential problems when scrolling is turned off: If you turn off scrolling in a frame, make sure all the content correctly displays on small monitors and small window sizes.
Problems on small screens: While frames can work on desktop machines, they don’t translate well onto small screens, such as mobile phones and PDAs.

In many cases, the benefits of frames can be duplicated in HTML without frames. This example illustrates how we go about evaluating the use of a new technology – we systematically weigh the tradeoffs of determine whether use of the technology is justified in each situation.