Surprisingly, I found very little research documenting the frequency of seemingly common (perhaps even standard) design practices such as the left-hand navigation bar, blue underlined links, and top-of-the-page global navigation. I was surprised because as a consultant working with clients, every project seemed to bump up against strongly held beliefs about what was “standard” on the web. I had my suspicions, but no data, that solutions being put forth as standard were common but by no means employed by all (or nearly all) sites. I wondered: Are de facto standards on the web myth or reality? I decided to investigate.
For my study (conducted as a graduate student at the University of Washington), I systematically analyzed the navigational interface of 75 leading ecommerce websites, across 15 consumer product categories. The sites selected in each category represented leading merchants with a well-known brand and a sophisticated web presence—sites that were deemed most likely to embody design best practices. I collected data along a sample browsing path, storing design attributes in a relational database system as I went. The data collection, which sounded simple in theory, was more complicated than expected. It involved understanding the function of all the navigational elements on the sample pages (a total of 315 were examined) and coming up with a descriptive scheme that accounted for the range of elements contained in those pages.
I collected most of the data during a concentrated period of a week and a half in May of 2002. The data included the type and style of navigation, where navigation was located on the page, the placement of common ecommerce functions, and labeling and icon use for ecommerce functions. The results showed that very few of the design practices studied were employed by more than 70% of the ecommerce sites in the sample. These characteristics can be seen in the table below.
|Logo linking back to homepage displayed in upper left corner||100% of sites|
|Global Search presented as a text field and button||93% of sites|
|Top or horizontal placement of global, top-level category links||87% of sites|
|Text rendered as a graphic for global, top-level links||76% of sites|
|Cart metaphor used for View Cart function||72% of sites|
Several characteristics occurred less commonly than expected. For example, only 45% of pages had breadcrumb navigation, and only 50% of pages used blue as the primary link color. HTML text links were underlined only 62% of the time, and only 37% of pages used a different color to indicate a visited link. With the exception of the company logo in the upper left corner, there was only very loose clustering for the location of common ecommerce functions such as View Cart, Manage Account, and Get Help.
Given the web’s lack of central control, the lack of standardization is probably not surprising. But the above findings represent just one snapshot in time. Will the web become more standardized? What are the usability risks of not following a de facto standard on the web? Should interface standards be adopted for the web as they have for desktop applications?
Where do “standards” come from?
The usual marketplace forces that lead to de facto standards—single, dominant vendors within a market—are missing in the web today. Still, there are clearly leading companies, such as Amazon.com, whose designs are widely copied. And while the data collected was not formally analyzed from this perspective, it seems that sites within a particular product category tended, at least graphically, to have similar designs. I suspect design similarities among sites stem from the largely untested belief that certain comparable or competing sites represent a benchmark, best practice, or “standard.” The homepages of Crate & Barrel, Pottery Barn, and Restoration Hardware (at least as of this writing) are examples of this kind of similarity.
The relationship between consistency and usability on the web remains a lightly researched area. At the end of my study, I was left with a number of nagging questions:
- At what point is a design practice so dominant that varying from it degrades the usability of a site? Are users expectations set when 90% of sites do something a certain way? Or does it require less frequency (80%, 70%, or even 60%)?
- How much deviation from a particular “standard” practice can occur without a loss in usability? For example, a study conducted by Michael Bernard clearly shows that users expect to find the logo in the top left corner of the page. But are they able to locate it just as quickly if it is in the top center the page? What about top-right placement?
- Are there particular aspects of web design where de facto standards have a higher impact on usability when compared with other aspects of design? For example, is it more important to keep location or labeling consistent?
The argument for standardization on the web usually rests on the benefits that interface standards have provided in the world of desktop software: lower development costs and higher usability. Development costs are lower because there are fewer unique design decisions that need to be made. For routine design decisions, designers can rely on standards published by platform vendors (such as Apple’s Aqua Human Interface Guidelines and Microsoft’s Windows User Experience). At least partially standardized applications on a given platform are, collectively, more usable because users can transfer part of what they know about using one application to another application.
However, as Jakob Nielsen has argued, the need for usability is even greater on the web than for desktop software. Web users are a much less captive audience. The costs to a user of switching to a different desktop application can be high, both in terms of the dollars the user spent purchasing the software and the time he or she spent learning the system. On the web, though, switching costs are minimal. As a result, poor usability on the web can have a more immediate and severe impact on a company’s revenue.
Design standards, therefore, seem like an attractive approach for improving the overall usability of the web. However, the web experience does not map directly to that of desktop applications. With the exception of games, most desktop applications consist of functions that help the user perform tasks rather than content designed to engage the user. Consider the differences between a spreadsheet program and an ecommerce site whose mission involves selling products and reinforcing brand image. Selling products and reinforcing a brand is a communications endeavor that involves making an intellectual and emotional connection with the audience. Making this connection successfully may mean going against conventional practice.
For example, on Nordstrom.com users put desired merchandise in a shopping bag rather than a shopping cart. Data from the study showed that 72% of sites use a cart (rather than a “bag” or “basket”).
Nordstrom.com’s shopping bag link, therefore, goes against common practice. Yet a shopping bag is much more representative of the offline shopping experience at Nordstrom. You do not shop at Nordstrom by wheeling around a shopping cart. In fact, the thought of doing so is somewhat absurd—carrying an elegantly designed Nordstrom shopping bag is an integral part of the (offline) purchasing experience.
Another, more offbeat, example is Spencer Gifts, a company that sells novelty items like costumes, lava lamps, and party gags. At the time I collected the data, conducting a search at spencergifts.com involved entering a keyword and clicking the eyeball that served as the Search button. This presentation of search is not only fun for users, it also reflects the genre of merchandise Spencer Gifts sells.
In short, adhering to standard (or at least common) practices in website design can be beneficial, but also has a potential pitfall: creating a generic experience that is emotionally uncompelling. On the web there is an inherent tension between creating a uniform experience across sites (which lowers development costs and increases usability) and creating a unique, compelling experience.
For the designer, the ultimate goal is to have data available to:
- Understand which practices are standard or very common.
- Understand the usability benefits of following those standard or common practices.
- Weigh the risk and benefits of violating the standard when there is a compelling reason to go with an unconventional design.
And, of course, potentially risky designs (particularly for frequently-used or important functions) should be always be evaluated through usability testing.
To help shed some light on existing design practices, I have published the results of my initial study as part of a new website, Web Design Practices. The site also contains links to related empirical studies—an area of the site I hope will grow as more research is conducted. My intent with Web Design Practices is for it to become a useful resource for the web design community—one that helps inform (rather than dictate) design decisions.