Mobility is Different
The original "mobile phone" was a single-blade pocketknife, good for only one thing: making telephone calls. Over time, it evolved into a Swiss Army knife, such that the modern "phone" is a device that can be used to take pictures, listen to music, watch videos, update your calendar, and an expanding array of other functions as both hardware and software expanded its capabilities.
(EN: This is essentially true, but I feel an important point is missed. There was a time when there were multiple devices, each of which had a single function: a phone, a pager, a PDA, a portable music player, a digital voice recorder, a camera, etc. It got to the point where one clothing company even designed a special pair of "tech pants" with pockets for multiple devices. The early "evolution" of mobile was simply to combine the various gadgets a person was carrying anyway - and the existing multi-use devices haven't done much beyond that, though my sense is this is a possible next step for unique capabilities to evolve on the platform, rather than being assimilated from other devices.)
Sticking with the Swiss Army metaphor, the author suggests that when you are designing the best possible screwdriver for a pocketknife, it is different than designing a "regular" screwdriver. People don't use the pocketknife version for the same tasks. (EN: And it's likewise unreasonable to expect that people will throw away their screwdrivers because there's one on their pocketknife.)
Likewise, the purposes for which an individual will use their portable computing device are significantly different than the purposes for which they will use a desktop (or notebook) computer. And in order to be effective for the purposes for which they are used, the applications cannot be designed in the same way.
While the design and software development processes may bear some similarity, it requires and entirely different mind-set. Of primary importance is to focus on the mobile users and their behavior, merely than supposing that the same principles can be applied to this new and vastly different medium.
MOBILIZING APPLICATIONS
The traditional cell phone, as a single-bladed pocketknife, is far from extinction. While the mobile channel is growing, it is still dominated largely by gadget-nuts and teenagers, whose enthusiasm is likened to that for a toy. For many users, they still have the attitude that "I don't need data services. Just give me a simple phone that has good reception and battery."
It's difficult to argue with that, because mobile devices are presently very poorly designed and of little practical value. The corkscrew on a Swiss Army knife simply doesn't work very well, and people simply do not have a need to pull the cork out of a bottle outside of their own kitchen. To them, it is entirely useless, and entirely unworthy of the investment.
The notion that the mobile channel is a substitute for the online channel is a serious fallacy that is all to widespread. Focus groups show that real consumers are painfully aware of the limitations of the mobile phone. Most are barely willing to read a long document on a full-sized monitor, and the task becomes painful on a miniature display. Also, the notion that users will be willing to pay to have a service on mobile that is freely available elsewhere is entirely misguided.
Presently, most mobile applications are merely miniaturized versions of desktop applications - and as result, most mobile applications are ill-suited to the mobile platform. This, too, stems from the misconceptions that users want the same functionality in both channels. More likely, the developers and designers want to provide the same functionality - so they can use the same code, so that development is cheaper.
There is also the notion that a mobile application can be a "stripped down" version of a desktop application, omitting the functions and features that cannot be easily accommodated by the device. Neither is this true - though the failure of such attempts has only led credence to the necessity of providing all the bells and whistles. The problem is not what can be done based on the capabilities of the device, but what the user wishes to do - and what they wish to do with the mobile device is fundamentally different from what they currently do with the desktop computer.
To be successful, mobile applications must depart from the "miniaturize" trend, as well as taking advantage of the specific capabilities of the mobile platform. Few change the default "sounds" played by their computer, but most users customize their ring tones. Few users take many pictures with the "Web cam" attached to their computer, but many take pictures with the built-in camera of their mobile devices. Text messaging is an annoying distraction on the desktop, but a popular feature on mobile devices,
WHAT IS 'MOBILE' ANYHOW?
The very definition of "mobile" remains unclear. By one standard, a laptop computer is a "mobile" device - but it is essentially used in the same way as a desktop. The standard of having wireless access is also unsatisfactory, as more devices (including desktop computers) can be connected wirelessly. Another attempt is to use "handheld," which seems to better capture the essence, but a tablet PC or a television remote control are then admitted.
A better approach to the definition of "mobile" is based on the behavior of the user, not on the device or the application. A mobile device is carried by the user, can be used in various locations, and in many instances can be used by a person while they are physically in motion (i.e., walking).
It's also suggested that communications capabilities are a significant factor. A digital camera or a portable music player are portable electronic devices, but are not considered part of the mobile channel.
Some of the specific qualities of a "mobile" device are:
- Personal - it generally belongs to and is used by only one person
- Communicative - The device can send and receive information, independently or via a connection to a communications network.
- Handheld - The device is portable, and can be used while being held in a single hand (even if users may prefer to set it down and use both hands, it is designed to be usable with one)
- Wakable - The device must be always-on or have instant-on capabilities from a "sleep" mode rather than a lengthy start-up routine.
The combination of these four features make the device an "ever present part of the user's life" that is constantly on their person or within arm's reach.
THE CARRY PRINCIPLE
The fundamental distinction between mobile-targeted design and design targeted for other platforms is The Carry Principle: the user typically carries the device, all the time. The Carry Principle has several implications on the device:
- Form. Devices are small, battery-powered, have some type of wireless connectivity, and have small keyboards and screens (if present).
- Features. Any information or entertainment features that might be desirable to have away from a computer or television, including television itself, will eventually get wedged onto the PCD. Devices evolve towards the Swiss Army knife model.
- Capabilities. The wireless connection, small size, and power constraints have made devices have slower connection speeds, slower processors, and significantly less memory than desktop computers.
- User interface. The small screen drives the device to a single-window user interface, so sharing information between applications is problematic.
- Proliferation. A personal, always-present device needs to match a user's needs, desires, and personality reasonably well. One form, one feature set, one user interface will not fit all.
The Carry Principle also has implications for the PCD users:
- User availability. The mobile user is more available for communications and application interaction than a computer user simply because the device is always present.
- Sustained focus. Because the user is doing so many things, there may not be sustainable time available for the device.
- Social behavior. Always-available connections has made attending meetings and dinner with friends a modified experience. Coordination across space allows both more and less social behavior.
Each of the above has implications for application design.
COMPONENTS OF A MOBILE APPLICATION
The consideration of the environment in which software would be used should be a consideration for any development effort, but is particularly critical to mobile.
The characteristics of the "desktop environment" are fairly well defined: a full-color monitor of certain pixel dimensions, keyboard and mouse, sound capabilities (speakers or headphones), a relatively fast network connection, and a specific operating system and a relatively small list of software options (browsers). The user is typically seated on an office environment, with his full attention focused on the computer - distractions are unusual and constitute a brief interruption in the task.
The characteristics of the "mobile environment" are significantly different. There is no standardization of devices (which can be expected to continue to evolve), nor any common environment in which they are used. The author lists a number of factors:
- The device (PCD for "portable communications device) has a unique physical design, capabilities, and application environment
- The PCD may have one or more "application platforms" consisting of an operating system communications technologies, and applications
- PCD output devices include a screen of varying size, a speaker, infrared emitter.
- PCD input devices include a keypad or small keyboard, touch screen, microphone, camera, RFID chip reader, GPS, etc.
- PCDs are networked via WiFi, Bluetooth, or cellular wireless.
- There may be a server infrastructure to support a given device, with interfaces to applications and information sources.
- The user may be walking down the street, riding on a subway, sitting in a meeting, or in any of a range of environments
- The user is not necessarily engrossed in the device or application, but may switch his focus among various tasks
The main difference, from a design perspective, is predictability: much is known, and can safely be assumed, of the desktop environment; whereas many of the factors affecting the mobile desktop defy predictability.