Aproximación al área de estudio

Improvements in mobile devices, especially smartphones, PDAs, and tablets mean that the experience of viewing web pages on these devices could be similar to the desktop. However, the limited capabilities of some mobile devices still causes issues with users’ experience when browsing website on mobile devices (Gomez, 2010b) especially those websites mainly developed for PC. This section discusses issues with current approaches of delivering and accessing web pages using mobile devices.

4.1.1 Dedicated-Different Versions of Pages for Mobile Devices

One approach to delivering web pages to mobile devices is to develop a dedicated separate version of mobile site for mobile devices as employed by sites such as Facebook and Air New Zealand. This ensures that the pages are suitable for viewing on mobile devices. However, this approach causes a few issues.

_{For the developers any update needs to be implemented multiple times, once for each}

different version of the pages. This is especially onerous if the sites have different versions of mobile sites for different types of mobile devices with varying capabilities.

48 Facebook has acknowledged the issue that maintaining multiple versions of sites is difficult and that it causes inconsistency between versions (see Section 2.4.1).

_{An update in one version might not be available on the other version(s) (see Section}

2.4.1). For the users, this can cause confusion if there is inconsistency with the full site or other mobile versions. For instance, our previous user trial revealed that the inconsistency of the location of certain items such as mutual friends between the Facebook standard site and the Facebook mobile site caused problems (see Section 3.3.4).

In short, having multiple versions of websites for different devices can cause confusion for the users and issues in maintaining the sites for the developers, particularly if the sites are frequently changed or updated.

4.1.2 Adaptation of Web Pages for Mobile Devices

Another approach to ensuring good viewing experiences on different devices uses adaptation techniques to reduce, customise, and adapt web pages for mobile devices. As discussed in Section 2.5, most of the adaptation engines proposed are meant (or only tested) for smart phones or PDAs. Some adaptation engines require the use of particular mobile browsers. In the case of client-side adaptation, specific types of mobile browsers or mobile devices are required, thus not all web capable mobile phones could benefit from the adaption. Among the issues with the existing adaptation methods are that the adaptation engines:

_{Re-segment or re-construct the initial page structure after adaptation by splitting the}

page into new subpages. This method reduces the need for long scrolling within a page. However, it also increases and adds to the hierarchical depth of the page. Having to go through more pages may cause users more clicking and loss of orientation within the overall site.

_{Present only a summary of content. This technique reduces the size of content on the}

page and allows users to find something they are looking for quickly. However, users have to navigate back and forth from the main page to access the full content.

4.2 Proposed Approach

Findings of our studies discussed in Chapter 3 showed that problems users encountered while accessing the web from their mobile could be categorised into two areas: design and infrastructure. Design issues include the different page appearance (structure, layout, and

49 terms used), and the extra navigation to get to the required content compared to the standard page accessed from the desktop. The infrastructure issues reported in our studies include slow access and download speed, which may be influenced by the device and network capabilities. This study will focus on solutions that address the problems users encountered in the design area. We do not address infrastructure issues. The design problems may be due to one or more factors:

_{Page structure of dedicated mobile version}

For many sites, the mobile version has a different overall page structure (different location of items) and different terms from the standard page for desktop viewing. This may cause the users confusion in finding the content, and require long scrolling and navigation through several levels to get to the right items or links. The mobile version may not be updated consistently with the standard version, resulting in different content; this may also confuse users.

Automatic adaptation or transcoding

In many situations, the page displayed on the mobile device is the outcome of an adaptation or transcoding engine, or the client browser auto adapting the page for the mobile device. This may result in jumbled page layout or content, cause confusion and increase navigation. The way content is delivered or structured may not be what users want and may cause frustration. The content may also be altered in ways the designers of the site had not anticipated.

Despite encountering problems, users are keen to access websites from mobile devices. Results from our previous study (section 3.3.4) showed that users want to have pages on their mobile devices that are similar in content and structure to those on the desktops.

We propose a solution to the following requirements determined from our earlier studies:

a. Ensure a similar page structure is delivered on all devices

If the page structures are similar between devices then users will be able to use familiar navigation pathways to find their items of interest. This will facilitate the ease of navigation.

b. Ensure consistency of terms used and the location of items on all devices

Having the same terms used under the same section (or for the main items) will prevent confusion as users swap between devices.

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c. Minimise items displayed and reduce navigating within a page

Displaying only the contents users require reduces the page size. This could reduce the scrolling and navigation required with the smaller screen and users could get to the required content more quickly.

d. Support users visiting on multiple different devices

Users have different devices and requirements, which may change over time. Being able to choose the items displayed based on the devices and requirements should improve their experience on the web.

To meet these requirements, we propose a server-side adaptation by prioritisation as an approach to adapt web pages to users’ needs. The adaption will not change the overall page structure but will allow some items to be removed. As discussed in Section 2.5.2, the adaptation can be done on the device, on a proxy server, or on the server. We chose a server- side adaptation for the following reasons:

_{The adaptation for devices is done automatically and works for any device regardless}

of the browser. The mobile device does not have to download the whole page first, which reduces the amount of data transfer. The adaptation does not require local processing, therefore, it reduces time taken to display, saves CPU (power and usage), and possibly battery life.

_{Installing a specific browser on the device or using a proxy server is not required.}

Users do not have to configure their device to first connect to a proxy.

_{Developers can control the adaptation as the page and prioritisation engine are on the}

same server.

Adaptation by prioritisation will allow users to prioritise page items that they want to display on a device. Users can set priority for each item (1 for high priority, larger numbers for lower priority). Low priority items would be removed from the page. This prioritisation will allow users to determine, for each device, what they want to display, and in which order. Users can always change their preferences.

For those sites that may be browsed casually using a mobile device, where users do not have their preferences set, default priorities set by the developer would allow initial adaptation that a user could then customise.

51 The prioritisation system will involve the following phases:

a. Users can set preferences for items of interest and the priority level at which items will be shown per page for each device.

b. The prioritisation engine reads the user preferences. If users have not set preferences, the system will use the default preferences set by the website developers for the device.

c. The prioritisation engine applies the preferences to each item, reorders the items according to the preferred items’ ranking and displays the prioritised page.

This method ensures that users have control of preferences. It also ensures that developers (or any stakeholders of the website development) can determine the items (or content) that are “prioritisable” so as not to interfere with the overall objectives of the page.

The prioritisation engine allows the overall structure of the page to be maintained on every version. The engine does not introduce new segments or subpages that would increase page depth and change navigation paths. The displayed items will be the same as on the full site to provide familiarity to users.

By default, multimedia content such as images will be delivered unchanged. Transformation rules and other media content adaptation approaches to handling the adaptation, for example, to omit/delete, compress, or convert the image could be implemented but are outside the scope of this study.