Overcoming Mobile Web Usability Challenges

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Overcoming Mobile Web Usability Challenges

By Raluca Budiu, Ph.D.

With the advent of new powerful mobile devices we finally have the tools to explore the web on a mobile phone. This is a huge opportunity for website developers to make the mobile web usable and get people to actually use them. In a recent international study that we conducted with the ‘early technology adopters’ , several of our users found mobile devices indispensable, and they were able (and willing) to use them to satisfy many of their needs on the go. Although early technology adopters are able to satisfy many of their needs on the go, for most users it is unfortunately still too hard.

Back in 2000, we at the Nielsen Norman Group tested the usability of the mobile web in a London-based user study and concluded that WAP usability failed miserably: users were struggling with basic tasks such as checking the news or local weather forecast. At the beginning of 2009, we conducted a second study that investigated the usability of the mobile web, hoping to find a much-improved landscape. This study involved 48 participants from the U.S. and U.K. who were invited to a usability lab and performed common activities such as finding information about TV schedules, trivia, getting directions to a restaurant, banking, and shopping. To our surprise, users were able to successfully complete only 59 per cent of the tasks. This number is substantially lower than the roughly 80 per cent success rate when testing websites on a regular PC today.

So what happened? Why is it so hard for users to be successful on the mobile web? Today we set the stage and explain why it’s difficult to design usable mobile sites. However, ‘difficult’ does not mean impossible — with the right knowledge, developers can create easy-to-use mobile websites. The art of mobile web design is very much in its infancy; that is why, at this point, it is vital to spell out the basic principles and to recognise the major difficulties that lie in front of us, so we best know how to deal with them.

Speed

One of the biggest reasons that users perform poorly on mobile devices is speed. Even people with fast smartphones are bound to encounter situations where their device is just too slow. This can be because the cellular network is too crowded, or because network coverage is poor in a given location. Wireless networks are still far from being ubiquitous, and users mostly rely on a cellular network signal to access the internet on their mobile phone.

When speed is slow, every single click matters. Every single click is one more chance of a dropped connection. Most users don’t have the patience to wait for a long time. If they are truly motivated to get to the information on your site, they may call a friend who’s sitting at a computer and ask him or her to find that information for them. Or they may simply call your company, if they can find your number. Most often, however, they will just quit your site and go somewhere else.

Because speed is so important on mobile devices, usability issues are amplified. What’s one extra click on the desktop? Although it is certainly not good usability practice to make your users do more work than necessary, your site will probably survive — users will not be that bothered by an extra click when they are using a PC. However, this is not true for mobile devices. Users will not forgive you if your site or application makes them work too hard or wait too long. Hence, when designing for mobile devices it is crucial to minimise interaction cost.

How do you get around slow speed? You can speed up the downloading of a page by using just a few images, if any, and no animation. Include only the information that is likely to be needed by your users and that adds value to the page. Streamline the interaction so that it involves as few clicks as possible (and thus as few downloads as possible). And, finally, give users feedback about the state of the download by showing them a progress bar – it won’t prevent them completely from moving on if the site is too slow, but it may delay them just a bit.

Screen

Another challenge when designing for mobile devices is that their screens are small. Typically, when you build a desktop website you can place a lot of information on one page, often operating under the assumption that different users have different goals and that all these goals should be easily supported. However, with a small screen, there’s only so much information that can fit. Some amount of scrolling is acceptable, but making users scroll through many screens is not a solution: most of the time, users will simply not do it.

So how can you deal with a small screen? You can think hard about what website features your users will most likely need when on the go, and structure your information accordingly. Make sure that the functionality you include on the website is relevant. For instance, if you have a fine jewelry shop, it’s unlikely that users will buy diamonds using their mobile device, but they may actually need the address of a brick-and-mortar store, and the opening hours, as well as a phone number. Give priority to information that is relevant for users when they are away from home.

Typing

On many mobile devices (feature mobile phones that have reduced keypads, but also some touch screen devices) typing is hard. We watched many users struggle to input a word, only to make one typo after another. One of our users unsuccessfully spent ten minutes trying to log in to a website, typing and retyping her user name and password. Logging in is especially difficult, because often passwords and user names are supposed to contain a combination of digits and letters as well as special characters. These are often challenging to type on the keypad of a mobile device.

Is there any way to get around typing problems? While you cannot completely eliminate the need for typing, there are instances when you can do the work for users — by prepopulating fields with sensible defaults or computing certain address elements (for example, in the U.K., the street and number are pretty much determined by the postal code) and filling them in for the users.

Mobile web browsers

Another challenge for the mobile web is that the native browsers for many mobile devices cannot display ‘full’ (desktop) sites, and mobile carriers end up mutilating these sites to make them accessible on mobile devices. A frequent result of this “optimisation” is a linearisation of the website, not unlike what is presented to blind users when they use a screen reader. In this case, the links on the page get presented in some random order and lose any salience that they used to have on the full site.

Browser limitations would not be such a big issue if sites had mobile variants that worked on different kinds of mobile browsers. Unfortunately, a lot of sites do not have mobile versions. And, to add insult to injury, even when they do have mobile versions, it’s not easy to get to them for a variety of reasons (for example, search engines use page-rank–like algorithms, and mobile websites are typically less linked to, hence getting lower ranks on search-results pages).

If the browsers are at fault, is there anything you can do? Yes, again. You can design websites specific to the mobile devices that you target, and you can work around the browser limitations. Indeed, our study shows that it pays off to do so -- success rates for mobile websites are 20% higher than for full, desktop sites.

Why does usability matter?

Usability means making your website or application easy to use by real people. The easier to use your software is, the more it’s going to be used. So how do you make your site easy to use by real users? Putting yourself in your users’ shoes can help, but is not enough. Most of the time, your users are different than you: developers have high technical skills and they are very familiar with the system they are developing; the average user does not have a degree in Computer Science (nor does she care to get one) and is interested in accomplishing her goals as fast as possible. In order to understand what matters to users and how you can help them attain their goals when they use your software, you have to watch them interacting to your system – that is, you have to do user testing.

Following usability principles and guidelines can get you on the right path toward designing software that is easy to use. We’ve offered some tips here that can help you overcome device or browser limitations. All involve serious consideration of how to make your site or application both usable and useful to your audience when they are on the move. Designing for mobile usability often involves some sort of compromise. For instance, there is a tension between (1) minimising clicks and making links accessible by putting them on the front page and (2) having a limited screen area where only a few links fit. The solution to that tension almost always involves a tradeoff that is specific to the kind of application or site that you are designing. Usability testing will give you the final answer regarding the right way to compromise.

Learn More

A 132-page report on Mobile Usability with 85 design guidelines is available for download from the Nielsen Norman Group. You can also find an in-depth course on mobile usability, including many video clips of test participants using a wide range of sites on many different devices, at the Usability Week 2009 conference in Las Vegas and Berlin.

About the author

Raluca Budiu is a User Experience Specialist with Nielsen Norman Group, where she presents tutorials on academic research findings, mobile usability, and cognitive psychology for designers; conducts research worldwide on usability for mobile websites and children’s websites; and consults for industry and government clients. She coauthored the NN/g report on mobile usability. Previously, Budiu worked at Xerox PARC, doing HCI research. There she built computational models of how people search for information in visualisations of large data structures. She also explored new ways of measuring information scent and conducted research on interfaces for social bookmarking systems and on the cognitive benefits of tagging. Budiu was also a user researcher at Microsoft Corporation, where she explored future directions and made strategic recommendations for incorporating user-generated content and social web features into MSN. Budiu has authored more than 20 articles and conference presentations on HCI, psychology, and cognitive science. She has a PhD from Carnegie Mellon University.

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