Usability
Considerations for Smart
Phones and PDA Phones
Converged wireless handheld devices that support voice and wireless data have been around for years. In some cases, disappointment has arisen from over promise and under delivery on the usability aspects of such devices (“yes I can surf the web, but no I don’t want to navigate 80 key presses to enter the URL then review my result on a 1 inch screen”). However with some forethought, an appropriately selected device has the potential to yield an increase in personal and professional productivity.
Here we focus on three key usability aspects:
Generally speaking, the differences in these three aspects define the difference between a Smart Phone and a PDA Phone.
Smart phones can be thought of as a device that is firstly a phone that also supports wireless data. PDA phones can be thought of as a device that is firstly a PDA that also supports voice. In this article we strive to identify the strengths and limitations of these two categories of converged devices.
The Keypad
The keypad is the primary means for interacting with a converged device. Smart phones typically have a keypad that can be operated using a single hand while a PDA Phone will typically require two hands.
PDA phones typically have a QWERTY keyboard (or a stylus touch screen). QWERTY is a standard layout for keys on keyboards and thumb pads. It is named for the order of the first six keys on the top row.
Smart phones typically have a numeric keypad using multi-tap or T9 for text entry. Both are physically comprised of the standard 12 key phone keypad (0-9, *, and #). Multi-tap uses multiple presses to select a character, e.g., pressing “3” once represents "D", pressing “3” twice represents "E", and pressing “3” three times represents "F". T9 uses predictive text entry from a numeric keypad. As you enter a word, the device will automatically compare letter combinations against a built in dictionary and guesses the word you were intending to use. T9 is usually tested to be measurably faster than multi-tap.
A multi-tap numeric keypad is required for one hand operation and will most likely provide a sufficient user experience if you will mostly use applications that do not require significant textual input. A QWERTY keyboard will be a must for even moderate levels of textual input. Beware that not all QWERTY keyboards are created equal and if you have large hands you will want to be sure to get a device with sufficient spacing between keys, lest you may be inadvertently pressing multiple keys. The smaller versions are sometimes referred to as micro-QWERTY keyboards.
Screen Size
The size of the screen “real estate” required by the types of applications that you will want to run will be a large component of your usability experience. Both Smart phone and PDA phones tend to support a QVGA screen. Quarter VGA has an image size of 320 x 240 pixels, or 1/4th the size of VGA (640 x 480 pixels). The actual screen real estate does differ between the two classes of devices. Smart phones will typically have a screen size under 2.5” while PDA Phones will tend to have screen sizes of 3”.
If most of your data usage is in the form of alerts, or used to retrieve property tax information, or a specialized application that receives information on drug interactions, then a Smart phone screen may be fine. If you need to review and edit documents then the larger PDA screen will be important. A touch screen for either a finger or a stylus can offer a lot of convenience for some types of applications.
In terms of web browsing, the actual choice of a mobile browser is important but Smart phone screens will generally work OK for viewing mobile pages. The larger PDA screen will work for some generic web browsing.
Application Support / OS
The device’s operating system is the primary determinant of the applications that can run on the device (memory and CPU are factors as well). Application can be delineated into the two categories: (1) general administrative uses, and (2) industry or functionality specific applications.
General administrative uses include contact management, checking flight schedules, tracking packages, receiving stock information, sports, or weather updates and can be supported by built-in applications or the included browser.
Industry or functionality specific applications will need to be downloaded to the device. In such cases, the operating system that executes on the device will have to be supported by the application. Symbian, Palm OS, BlackBerry, Windows Mobile Smart Phone Edition, Windows Mobile Pocket PC Phone edition and Linux are the most common converged device operating systems. The wireless operators also offer there own business or entertainment applications that can be downloaded and activated over the air (OTA). For the applications that you acquire independently, or through the operator, the device may need to also support one of the two popular mobile application platforms, Brew or J2ME (Java). Applications that run on Windows Mobile Smart Phone Edition will also run on the Pocket PC Edition but not necessarily vice versa.
Examples of Smart Phones and PDA phone
Examples of Smart phone devices as defined in this article include the HTC Faraday 2125, RIM BlackBerry 7130c, and the Samsung i320. HTC, the High Technology Company of Taiwan makes nearly all of the Windows based phone devices on the market, usually re-branded under a different name. Cingular, as an example, distributes the HTC 2125 re-branded as the Cingular 2125.
Examples of PDA phones as defined in this article include the HTC MDA 8125 / UTStarcom XV6700 /PPC6700, RIM BackBerry 8700, Palm Treo 650, Palm Treo 700w, Palm Treo 700p, Samsung i730 and Samsung i830. The HTC MDA is a GSM phone re-branded by Cingular as the Cingular 8125. The UTStarcom versions, also made by HTC, represent the CDMA counterpart with the XV6700 offered by Sprint and the XV6700 offered by Verizon Wireless.
Two phones that don’t quite fit the distinguishing factors between Smart phones and PDA phones as outlined in this article are the Motorola Q Phone and the Nokia 9300. The Motorola Q phone does have a QWERTY keyboard but runs the Smart phone version of the Windows Mobile operating system. The Nokia 9300 is, in a way, two-devices-in-one. On the surface, it looks like a Smart phone with a 128x128 screen and runs the Symbian Series 40 operating system, in its “closed” mode. But this device is hinged on one side and opens up into a very large (by PDA standards) 640x200 pixel screen on one side of the hinge, and a roomy QWERTY keyboard on the other side of the hinge. In this “open” mode, the Nokia 9300 executes the Series 80 version of the Symbian operating system.
Summary
In this article, we have looked at the differences between Smart phones and PDA phones from a usability aspect. We focused on data input to the device via the keypad, the screen size and gave some consideration to the operating system in the context of supporting the applications that are important to us.
If it is necessary to operate the device with one hand, such as while driving, and most of your data comes in the form of alerts (stocks, weather, specialized applications) or video downloads, then a Smart phone may be the right device for you.
If you need to enter moderate to heavy amounts of data, such as completing specialized forms, download and view documents, retrieve records or data entry into specialized forms or browse the Internet, then a PDA Phone may be the right device for you. Headsets can alleviate the awkwardness of holding the relatively larger device up to your ear to talk, and in conjunction with setting the device to auto-answer for incoming calls, can offer some level of hands-free operation.
Appropriately selected, a converged voice-data handheld wireless device can fulfill the promise of substantial personal and professional productivity.