I’ve been asked for advice on choosing a PDA for teaching and learning by a number of other educators, and I wrote this as an off-the-cuff response to one such enquiry. I’ll try to write something more formal at a later date!
The PDAs that are best suited to a student group’s learning needs will depend on the kinds of activities you’d like them to be able to accomplish. However, if you’re “exploring” all of the possibilities, get a pretty fully-featured PDA so that you can try out lots of different approaches without limitations – ideally, you’d even get two PDAs so that you can also experiment with connecting them together to share information between mobile devices over a wireless network.
The following attributes of PDAs are in rough order of importance for teaching and learning purposes (in my personal opinion!).
Connectivity
My personal philosophy regarding mobile learning places connectivity as one of the fundamental functionalities of most m-learning activities. This is because connectivity (to both information/resources, and people) enables the ad-hoc sharing and retrieval of information – supporting a social constructivist approach to learning. With connectivity options, a mobile learner can retrieve “just in time” learning from a remote source – they don’t have to load software or information onto their device before they head out the door. They can also exchange information with other users on the fly, for example, in a classroom or in the workplace, without having to use an intermediary computer to do so.
Connectivity is enabled by:
- Most primitively, a mobile device can be connected to a PC via a cable. This isn’t very mobile, but can be quite practical – for example, to backup a mobile device’s contents, or to store information that has been gathered using the mobile device.
- Also primitive, exchange of information between devices can be achieved by sharing a common solid-state memory format. This is like swapping floppy disks to transfer information.
- Most PDAs use Secure Digital (SD) cards… however, there are three different sizes! (Adaptors are available to enable smaller SD formats to be read in larger SD card readers – but obviously, not the other way around).
- “MicroSD” (Transflash) cards, which have a maximum capacity of about 2GB (although I’ve only seen 1GB cards sold in Canberra). Writing to and deleting data
regularly from these reduces their lifespan.
- “MiniSD” cards, which have a maximum capacity of about 4GB (although I’ve only ever seen 3GB cards sold in Canberra). I believe these may also have issues with writing and deleting.
- SD cards (full size) have a maximum capacity of 8GB (only seen 2GB cards sold in Canberra). They are the most durable of the SD form factors.
- Wireless connectivity allows devices to share information by sending it through the air – without any solid-state mechanism. Wireless connectivity can be used to share information with normal PCs, as well as many other mobile devices.
- Infra-red is a legacy (old) technology. It’s slow and requires line-of sight between the devices to exchange information, with a maximum distance of about 2 metres. Exchange of information over infra-red is free of any cost.
- Bluetooth is a “personal” wireless technology based on radio waves, and does not require line-of-sight alignment. It’s faster than infra-red, but only works within 10 metres of other devices, and cannot be used to access Internet services. Exchange of information over Bluetooth is free of any cost. Bluetooth is commonly found in mobile phones as well as PDAs, enabling a mobile phone to function as an “extension” of a PDA – for example to take photos, video, send and receive messages, or even connect a PDA to the Internet.
- WLAN (a.k.a Wi-Fi or 802.11) is a “local” wireless technology based on radio waves, and does not require line-of-sight alignment. It’s even faster than Bluetooth, and works out to about 100m (more or less, depending on the number/types of barriers between connected devices). The fastest, longest-range WLAN currently deployed in mobile devices is “802.11g”… however, a new “802.11n” protocol is on the way that would enable WLAN devices to communicate over, potentially, several hundred metres. This would be, however, a hardware, rather than a software, upgrade (would require additional/new hardware to be purchased to upgrade). WLAN can be used to connect mobile devices over longer distances. WLAN functionality is rarely found in mobile phones (though it is available in some). Connecting devices using WLAN is free of charge. WLAN can also be used to connect devices to the internet using a “Wireless Access Point” (a.k.a. “Hotspot”) In these cases, connection to the wireless access point is free, but access to the Internet may entail some cost. There are free wireless access points in Canberra – notably, the “NERDBAND” network at the Pancake Parlour in Civic, and Café Del Marco in Dickson, as well as in many other cities (e.g. Australian on Collins shopping mall in Melbourne). Voice-Over-IP and many messaging programs work on WLAN-connected devices to enable communication with other people over the Internet or between locally networked units.
- 2G Mobile Phone access is enabled in most Symbian devices (Nokia phones) and in many Windows Mobile smartphones. It allows a PDA to be used like a mobile phone, to make and receive calls, messages, and access the Internet using GPRS or EDGE (faster than GPRS) technologies. You get connectivity anywhere you have a mobile phone signal. However – connectivity *always* costs money.
- 3G Mobile Phone access is the latest in mobile connectivity. It’s the fastest of all of the connectivity options here and has the widest availability – you can access other people and information services anywhere you have a signal, and it’s fast enough to make video calls and practically download rich media such as audio and video. Connectivity always costs money.
Camera
Many mobile devices such as phones and PDAs now come with an integrated camera. These do an increasingly better job, with the best mobile devices packing 3.2 megapixel cameras (good enough to take A5 photo-quality snaps) – although these are found in mobile phones, it won’t be long before these are in PDAs, which currently have a maximum resolution of about 2 megapixels. All camera devices I’m aware of take both photos and video. These can be used for many learning activities, such as recording procedures for later review, or recording a learner doing a task for later, or remote, assessment. I’d regard a built in camera with a minimum resolution of 1.3 megapixels as a very useful feature in a mobile learning device.
Battery Life
This can be really, really important. If the batteries die, it doesn’t matter what features your PDA has… it’s only good as a paperweight. Choose a model with a reasonable battery life, and turn off or turn down features you aren’t using: wireless connectivity, bright screen, and running the processor at full speed all (dramatically) reduce battery life, by as much as 75%. Buy a second battery and always keep it charged and on hand. This will also extend the life of your PDA, as it will reduce battery fatigue that comes with charging and discharging a single battery.
Platform
There are three main platforms for “smart” digital devices at the moment:
- Palm specialise in a PDA-based system, Palm OS, which uses a stylus to interact with the device.
- Nokia make “smartphones” based on the Symbian OS, which do not use a stylus to interact with the device.
- “Pocket PCs” use the Windows Mobile OS, which has both PDA and “smartphone” variants, and usually uses a stylus to interact with the device.
There are pros and cons to each platform. I personally use a Windows Mobile-based PDA – if you try out a few PDAs and prefer this platform, I recommend the latest version (Version 5) – the previous version (2003) has some inherent flaws that have been addressed by Version 5.
Choice of platform is likely to be influenced by what software you choose to run (some programs only work on one platform), and how much you like the interface each OS presents. There’s also an issue with social compatibility: if most other people at an organisation have Windows Mobile devices, you might like to also choose a Windows Mobile device so that you can swap recommendations on software, for example.
Screen/Display
Three factors here are important: the resolution, and the physical size, and the image quality.
- Resolution affects how sharply images and text are rendered on the screen – higher resolution means more information can be displayed on the screen, and more crisply.
- However, the actual physical size of a mobile screen is more likely to be an issue for accessibility reasons. Smaller screens squeeze text and images into a smaller frame, making them more difficult to read or view. If eyesight is an issue, larger screens can be easier to use, even with less resolution, that a high-resolution screen that’s very small.
- Screen quality is to do with how well colours display on the screen, and how bright the backlight is. Brighter backlit screens are easier to read in well-lit environments than poorly backlit ones. Choose a bright screen if you’re likely to be using the PDA in daylight, for example. You can reduce the brightness on PDA screens to conserve batteries.
Performance
The speed of the processor, the amount of memory, and the amount of built-in storage capacity affect a mobile device in much the same way as they do a normal desktop PC… the higher the better.
These are just some initial thoughts – I will try to put together something more formal for other teachers when they’re evaluating PDAs for teaching and learning, but I hope this helps somewhat!
Make sure your curriculum is up to date especially when teaching math, technology or biology as these fields are constantly evolving.
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This isn’t news by any stretch, but worth posting – just for the record. 
