Platforma průmyslové spolupráce
CZ.1.07/2.4.00/17.0041
Název
Specific aspects of designing applications for mobile devices
Popis a využití
• úvod pro obecný design aplikací
• výuka: vývoj pro mobilní platformy
Jazyk textu
• anglický
Autor (autoři)
• Lucia Mačková Tokárová
Oficiální stránka projektu:
• http://lasaris.fi.muni.cz/pps
Dostupnost výukových materiálů a nástrojů online:
• http://lasaris.fi.muni.cz/pps/study-materials-and-tools
Specific aspects of designing applications for mobile devices
Mgr. Lucia Mačková Tokárová
In the last couple of years, the mobile devices have become more and more important part of people's
everyday lives. For a long time, their primary purpose was communication in the form of voice calls and
text messages. Mobile devices were fairly simple compared to personal computers. However, with the
emergence of smartphones and tablets, the complexity of these devices has increased dramatically.
They have become significantly more powerful, as well as affordable.
Furthermore, the modifications of infrastructure and distribution of software for mobile devices have
expanded the base of application developers. As a result, mobile applications have become more
mature, empowering people to perform more advanced tasks. Therefore, it is now more common to use
mobile devices in situations, which were widely associated with desktop environment – for many
people, it is currently more common to use their smartphones and tablets to browse websites, access
social networks and read articles rather than use personal computers (Wroblewski, 2011).
On the other hand, the portability of mobile devices has also stimulated the emergence of new, truly
mobile use cases. Most of the current devices are equipped with sensors, which can collect data about
users location and environment. This data can be used as parameters and provide contextual
information about user's actions.
All these changes have initiated tremendous growth in the area of mobile design and development.
However, the principles of designing and developing applications for mobile devices are different from
traditional software development. This report presents the selection of the fundamental issues, which
must be considered in the process of designing user interfaces of mobile applications.
Development perspective
From the development perspective, there are currently three basic approaches for implementing mobile
applications.
● Web applications for mobile devices utilize standard Web technologies, such as HTML5, CSS, and
JavaScript. It allows for a development of one version of the application, which runs on any
device with a conventional Web browser. Some of the main advantages include automatic
updates, remote data processing and saving memory space. On the other hand, this method still
requires at least minor front-end adjustments for different categories of devices and does not
take a full advantage of unique mobile features, such as multi-touch interactions, a camera, or
mobile sensors. This approach can be useful when the application relies heavily on content
presentation and basic operations, such as sending text messages.
● Native applications are developed separately for each supported platform, using development
tools and programming language specific for each given platform. It is currently the most
common approach, because it allows to access the specific features of mobile devices. The
performance of applications, the user interface, and even the extend of functionality can be
optimized for each platform and category of devices. However, it all comes at the expense of
longer time, and subsequently an increase in development cost.
● Hybrid applications are theoretically supposed to combine the advantages of both previous
methods by embedding Web applications inside native containers that provide access to the
features of a native platform. In reality, due to the lack of standards and evolving nature of
conventions in mobile industry, this approach still demands adjustments and optimization of
applications for various end user devices. As a result, this option is currently used only
sporadically, usually for content-heavy applications with simple operations.
It is apparent that each approach presents specific advantages and disadvantages. The selection of the
best technique depends on the characteristics of the particular project. Yet, it is often difficult to choose,
which platforms should be supported and what techniques will be used. The problem is that these
implementation questions often overshadow other fundamental decisions associated with users' needs
and requirements. As a result, the usability and user experience are negatively affected, which in turn
decreases the likelihood of user adaptation.
Design considerations
In order to maximize the usability of mobile application and provide positive mobile user experience, it
is important to deal with a several design considerations. Many of them are associated with differences
between desktop and mobile devices and user interfaces, such as different form factors and interactions
styles. However, many differences are also caused by specific users' needs and requirements based on
mobile context of use. The following list provides the selection of the most substantial issues that need
to be considered throughout the process of designing applications for mobile devices.
Display size
Mobile devices have significantly smaller displays compared to desktop computers. It means that the
content and features of mobile applications must be strictly prioritized, showing only the essential
elements on each screen. The discoverability of advanced features is considerably reduced (Norman,
2010), since users are provided only with basic functionality and advanced features remain hidden.
Other difference is the wide variety of display resolutions and aspect ratios. The design must be flexible
to accommodate the elements of the user interface and take advantage of available space on various
devices, and at the same time it must remain readable and provide enough space for comfortable
interactions.
Touch screens
Most of the current touch-screen mobile devices are controlled by users' fingertips. As such, interactions
are less precise and more error-prone. In order to avoid slips and unintended actions, the controls on
touch-screen devices must be larger and further apart compared to controls on desktop user interfaces.
Moreover, the fingers cover a large part of the screen, which directly affects the user interface design
decisions. The layout of the user interface must be adjusted so that the most frequently used controls
are placed within the comfortable reach and the content is not covered by users' hands.
Gestural interactions
The concept of direct manipulation allows users to learn basic interactions (e.g. tap to open, or swipe to
scroll) easily by reducing the cognitive load associated with hardware controls and peripheral devices.
Nonetheless, touch-screen interactions are less obvious when it comes to complex operations. The
range of possible interactions and the precise dynamics of execution are difficult to discover and
subsequently to recall (Norman, 2010). Furthermore, the touch-screen interaction design conventions
are still evolving, so it can hardly be taken for granted that users will be familiar with advanced
interactions. For now, advanced interactions (such as pull to refresh, squeeze to close an application, or
swipe to delete an item) are used mainly as alternatives or shortcuts for more experienced users.
Virtual keyboards
A vast majority of current touch-screen mobile devices does not contain physical keyboard. Instead,
they are equipped with virtual keyboards, which is loaded on the screen on demand. This approach is
space-efficient, because when the typing is not required, almost the whole size of the mobile device can
be used for content presentation. However, the text input on soft keyboards is more error-prone and
less comfortable, because it does not provide physical feedback. As such, it is important to minimize the
amount of textual input and consider alternatives, such as voice, gesture, or sensory input.
Sensors
Modern mobile devices are equipped with a number of sensors, such as GPS, accelerometer, gyroscope,
digital compass or proximity sensor. These sensors can collect data about users location and
environment, and as such, they can automate or ease various operations. However, it is important to
take into account the variety of mobile devices. The presence of particular sensor cannot be taken for
granted – some models do not contain the whole range of features and also, the features might be
turned off by user. Therefore, it is often necessary to provide alternatives, which cover all possible
scenarios.
Context of use
Sessions with mobile applications are short and occur under varying circumstances (Böhmer et al, 2011;
Oulasvirta et al, 2005; Müller et al, 2012). In contrast with desktop and web applications, users cognitive
resources are usually not focused solely on the mobile user interface. Their attention might be
distracted by their surroundings and other actions they are performing.
Under these conditions, clarity and straightforwardness of task flows play substantial role. On the other
hand, it is important to find strategies to make users aware of more efficient interaction flows, which
may be less intuitive but more useful in the long run.
Platform differences
The user interface design guidelines and conventions of mobile operating systems are not universal.
Each platform provides its own set of standards based on specific size and hardware features of physical
devices. As the mobile market grows and changes, the standards evolve.
In order to support multiple mobile operating systems with a native application, the design and
development process must be handled separately for each platform. It increases the complexity of the
work and time requirements.
Conclusion
The principles of designing and developing applications for mobile devices are substantially different
from traditional software development. On one hand, the discrepancies are based on characteristics of
target devices – the physical attributes of mobile devices and interaction styles are significantly different
from traditional desktop computers. On the other hand, they are caused by specific users' needs and
requirements associated with mobile context of use.
Designing applications for mobile devices opens new possibilities, but also introduces new challenges to
designers and developers. In order to take full advantage of unique characteristics of mobile devices and
their role in users' everyday lives, it is important to consider a wide range of aspects and integrate their
implications throughout the whole process of application design.
Bibliography
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International Conference on Human Computer Interaction with Mobile Devices and Services (MobileHCI
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Müller, H., Gove, J.L. and Webb, J.S. 2012. Understanding tablet use: A multi-method exploration. In:
Proceedings of the 14th International Conference on Human Computer Interaction with Mobile Devices
and Services (MobileHCI 2012), September 2012. San Francisco, CA, USA:1–10.
Norman, D. 2010. Natural user interfaces are not natural. ACM Interactions, 17(3):6–10.
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