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XueCheng Qiu
ARCS
Final Essay
March 10, 2010
The User Interface of Android OS & iPhone OS
With the promotion of 3G, smart phone come into the universal stage. Only
use phone to communicate can not meet people's needs now, aesthetic appearance, a
wide range of functionality and user interface has been widespread concerned.
Depend on good user interface and user experience; iPhone pioneered the new era of
smart phone. But in 2008, a new open-source smart phone operation system was born,
which called Google Android, it’s rapid development unavoidable to have a direct
competition with iPhone OS. This paper analysed each elements of user interface of
iPhone OS and Android OS, it will shows which is better and the advantages of
android UI.A user interface (UI) is the system by which people (users) interact with a
machine. The user interface includes hardware (physical) and software (logical)
components. User interfaces exist for various systems, and provide a means of: Input,
allowing the users to manipulate a system, and/or; Output, allowing the system to
indicate the effects of the users' manipulation (Boundy). Generally, the goal of
human-machine interaction engineering is to produce a user interface, which makes it
easy, efficient, enjoyable to operate a machine in the way, which produces the desired
result. This generally means that the operator needs to provide minimal input to
achieve the desired output, and also that the machine minimizes undesired outputs to
the human .The original cell phones made one single break with the interface of the

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wired phones that had come before: The user dialed, then pressed Send, instead of
dialing “live” as had been done historically. Added later were such niceties as
keyboards for message and email construction, borrowed whole, again, from the
wired world. (Even the Send button was borrowed from earlier Radio-Telephone
technology.)Occasionally, bits and pieces of interface innovation have found their
way into subsequent cell phones, but no one has ever revisited Bell Lab’s pushbutton
phone design from the 1950s with its upside-down adding machine keyboard (with
the exception of Smart Phones, based on the 1870s typewriter keyboard).Today, more
and more phones built-in touch screen , this is the trend. We can use touch screen to
directly interacted with phones, so the user experience are mostly depending on the
user interface.
The user interface of iPhone OS is based on the concept of direct
manipulation, using multi-touch gestures. Interface control elements consist of sliders,
switches, and buttons. The response to user input is supposed to be immediate to
provide a fluid interface. Interaction with the OS includes gestures such as swiping,
tapping, pinching, and reverse pinching. Internal accelerometers are used by some
applications to respond to shaking the device (one common result is the undo
command) or rotating it in three dimensions (one common result is switching from
portrait to landscape mode). There is no concept of starting or quitting applications,
only opening an application from the home screen, and leaving the application to
return to the home screen. It is possible to force an application to quit by holding
down the power button until the "slide to power off" slider appears, and then holding
the home button down, however. While some multitasking is permitted it is not
obtrusive or obvious. However, it is limited to Apple's own applications. Third-party
applications are quit when left (Wikipedia). In an Android application, the user

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interface is built using View and ViewGroup objects. There are many types of views
and view groups, each of which is a descendant of the View class.View objects are
the basic units of user interface expression on the Android platform. The View class
serves as the base for subclasses called "widgets," which offer fully implemented UI
objects, like text fields and buttons. The ViewGroup class serves as the base for
subclasses called "layouts," which offer different kinds of layout architecture, like
linear, tabular and relative.A View object is a data structure whose properties store the
layout parameters and content for a specific rectangular area of the screen. A View
object handles its own measurement, layout, drawing, focus change, scrolling, and
key/gesture interactions for the rectangular area of the screen in which it resides. As
an object in the user interface, a View is also a point of interaction for the user and the
receiver of the interaction events. (Android Dev Guide). Android is a multi-task
system, it can run several applications at same time like PPC or PC.

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Figure 1. iPhone Lock screen Figure 2. Android Lock screen
Figure 1 and figure 2, it shows the iPhone and Android has some affinity in
locks screen mode, they all contain a slide bar, a clock set, and a status bar on the top,
when slide it we could enter the home screen of system, in Android, it will trigger an
UI interaction (Vibration), in addition, Android has a extra slide bar which control
the sound. It works conveniently when we need the phone be muted, for example,

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when we having a meeting in company. That is the advantages of Android UI.

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Figure 3. iPhone home screen Figure 4. Android home screen and widges
In figure 3, it contains a home screen (rendered by "SpringBoard") with
application icons, and a dock at the bottom of the screen, showing icons for the
applications the user accesses the most, is presented when the device is turned on or
whenever the home button is pressed. The screen has a status bar across the top to
display data, such as time, battery level, and signal strength. The rest of the screen is
devoted to the current application On January 15, 2008, Apple released software
update 1.1.3, allowing users to create "Web Clips", home screen icons that resemble
apps that open a user-defined page in Safari. After the update, iPhone users can
rearrange and place icons on up to nine other adjacent home screens, accessed by a
horizontal swipe. Users can also add and delete icons from the dock, which is the
same on every home screen. Each home screen holds up to sixteen icons, and the dock
holds up to four icons. Users can delete Web Clips and third-party applications at any
time, and may select only certain applications for transfer from iTunes. Apple's
default programs, however, may not be removed. The 3.0 update adds a system-wide
search, known as Spotlight, to the left of the first home screen. Almost all input is
given through the touch screen, which understands complex gestures using multi-
touch. The iPhone's interaction techniques enable the user to move the content up or
down by a touch-drag motion of the finger. For example, zooming in and out of web
pages and photos is done by placing two fingers on the screen and spreading them
farther apart or bringing them closer together, a gesture known as "pinching".
Scrolling through a long list or menu is achieved by sliding a finger over the display
from bottom to top, or vice versa to go back. In either case, the list moves as if it is
pasted on the outer surface of a wheel, slowly decelerating as if affected by friction.

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In this way, the interface simulates the physics of a real object. Other user-centered
interactive effects include horizontally sliding sub-selection, the vertically sliding
keyboard and bookmarks menu, and widgets that turn around to allow settings to be
configured on the other side. Menu bars are found at the top and bottom of the screen
when necessary. Their options vary by program, but always follow a consistent style
motif. In menu hierarchies, a "back" button in the top-left corner of the screen
displays the name of the parent folder (Wikipedia). Figure 4 is the Android home
screen, this is a big different from iPhone, because iPhone has no desktop concept.
This is one part of android desktop(android UI contain several desktop area, controls
by slide form right or left.), the users could customize the desktop element(icons,
widges, wallpapers or shortcuts).App Widgets are miniature application views that
can be embedded in other applications (such as the Home screen) and receive periodic
updates. These views are referred to as Widgets in the user interface, and you can
publish one with an App Widget provider. An application component that is able to
hold other App Widgets is called an App Widget host. The screenshot below shows
the Music App Widget.
A widget is a View object that serves as an interface for interaction with the
user. Android provides a set of fully implemented widgets, like buttons, checkboxes,
and text-entry fields, so you can quickly build your UI. Some widgets provided by
Android are more complex, like a date picker, a clock, and zoom controls. But you're
not limited to the kinds of widgets provided by the Android platform. If you'd like to
do something more customized and create your own actionable elements, you can, by
defining your own View object or by extending and combining existing
widgets(Android Dev Guide). The richness third part widges of android was greatly
simplifies the user actions, we could directly read the RSS feed, twitter or SNS web

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sites via the widge without any operation. The red arrow in this figure shows two
official widges ,which control the music player and power switch, The users could
click the widges to switch the Wifi, Bluetooth, GPS or brightness(we also be able to
customize the power widge), so we could control the hardware functions though the
widge in stead of enter the setting menu to change it. This is much convenience than
iPhone OS UI. iPhone also have widges but it have been set in the main menu, if it
have too many applications we had to spend more tome to find the widges (It
combined the home screen and application menu)The bottom of the screen is the
application menu, when you tap it, your application icons fly into place to take over
the desktop in their own grid, and you can scroll them back and forward as if they
were on a 3-D cube, shown here. Android 2.1's Live Wallpapers move and react in
different ways when you touch the desktop--again, not strictly useful, but they make
the phone feel as if it is alive in your hand and responding to your every action.
Figure 5. Android application menu

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Figure 5 is the application menu, lists all applications that installed in mobile phone.It
has some satisfying eye candy that doesn't necessarily make you more productive, but
does make the phone more fun to use.
Figure 6. The "Push notification" of iPhone
Notification System is the most important part of mobile phone UI, the
notification system in iPhone contained two parts: Status bar and "Push notification”,
The status bar of the top shows the power, signal, and time. Push Notification allows
an application to listen for messages being 'pushed' to it from the server. The iPhone
does not allowed to run multiple applications at once, but through Push Notification,
the apps can provide uses even when they aren't running. This is similar to the mail
application that comes with the iPhone. It can receive mail and alert you that new
mail is in your inbox even if you are running other app (Nations). Traditionally, when
an application is running on a mobile device it will alert the user in real time when
there's been a change or something needs their attention. With Apple's SDK (past,
present, and immediate future), developer-made apps cannot run in the background,
and therefore cannot ping for data unless you're running them explicitly. The solution
Apple announced is a bit of a compromise, ferrying notifications through Apple's

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servers instead of locally on the user's hardware. Any messages from developer apps
get piped into user's phones in one of three different types of notifications--counters
badges (for something like a new e-mail message), audio cues, and pop-up messages
that look similar to text alerts.
Figure 7. Toast Notification of Android UI
Notification System in Android contains three part: First, Toast notification, A toast
notification (Figure 7) is a message that pops up on the surface of the window. It only
fills the amount of space required for the message and the user's current activity
remains visible and interactive. The notification automatically fades in and out, and
does not accept interaction events. Because a toast can be created from a background
Service, it appears even if the application isn't visible.
Figure 8. Status bar of Android UI

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Second, Status Bar. A status bar (Figure 8) notification adds an icon to the system's
status bar (with an optional ticker-text message) and an expanded message in the
"Notifications" window. When the user selects the expanded message, Android fires
an Intent that is defined by the notification (usually to launch an Activity). You can
also configure the notification to alert the user with a sound, a vibration, and flashing
lights on the device. This kind of notification is ideal when your application is
working in a background Service and needs to notify the user about an event. If you
need to alert the user about an event that occurs while your Activity is still in focus,
consider using a Dialog Notification instead.
Figure 9. Dialog Notification of Android
Third, Dialog Notification (Figure 9).A dialog is usually a small window that appears
in front of the current Activity. The underlying Activity loses focus and the dialog
accepts all user interaction. Dialogs are normally used for notifications and short
activities that directly relate to the application in progress. The user should use a
dialog when you need to show a progress bar or a short message that requires
confirmation from the user (such as an alert with "OK" and "Cancel" buttons). You
can use also use dialogs as integral componenents in your application's UI and for
other purposes besides notifications. For a complete discussion on all the available
types of dialogs, including its uses for notifications, refer to Creating Dialogs
(Android Dev Guide).

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Figure 10. Trend for Android
To compare with the lock screen, Android has a more usable interface, and
about the home screen, iPhone combined the home screen and application menu, it
will be very inconvenient when the user installed a large number of applications, but
have a Linux like desktop and an application menu, it will maximize the functional of
widges and short cuts. Depending on the muti-task system, Android also could show
the notifications on widges, status bar could show the multiple notifications, and the
user also could customize the status bar to show the running applications, this is a big
advantages that compare with iPhone. The toast notification helps user more easier to
get more necessary information of the interaction. Between Android UI and iPhone
UI, Android have many advantages in UI interactive and user experience, The
explosive growth in the market share of android is the most powerful evidence(see
figure 10). 2010 will becoming the year of android. Thanks to the open source project,
the more and more experts could improve the android UI, so, as time goes by, more
advantages of Android UI will appears.

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Work cited

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Android Dev Guide,(2008).
Retrieved from
http://developer.android.com/guide/topics/ui/index.html
Boundy,D.E.(1991).A taxonomy of programmers, ACM SIGSOFT Software
Engineering Notes, 16(4) 23-30.
Dave,M., Jeff,L.(2009). Beginning iPhone 3 Development: Exploring
the iPhone SDK (1st ed.). Apress. pp. 584. ISBN 1430224592.
Nations,D.,(2010)What is Push Notification. Retrieved from
http://www.examiner.com/x-13879-iPhone-Examiner~y2009m7d7-What-is-
Push-Notification
Wikipedia,iphone. Retrieved from :
http://en.wikipedia.org/wiki/Iphone#User_interface
Wikipedia,iPhone OS. Retrieved from:
http://en.wikipedia.org/wiki/Iphone_os#User_interface