Choosing a digital device: phone, smartphone or tablet
The decision to use a smartphone, tablet or a basic mobile phone is determined by the goals and type of data being collected. Basic phones are only able to receive and share simple SMS text data, while android phones enable the use of complex data collection forms and can collect video, GPS, audio and photos.
However, smartphones are much more costly, have a lower life expectancy and are less likely to be widely available.
Smartphone technology is advancing rapidly, and devices can vary greatly in price, robustness and functionality. Therefore if you choose to use a smartphone or tablet, this website does not promote one model; rather it offers a set of criteria that should help you decide which is most appropriate for the project.
Please click the links in the list below to see the details for these criteria.
- Battery life
- Memory (phone and external SD capabilities)
- Compatibility with software applications (e.g. Open Data Kit or Sapelli)
- Durability and robustness (e.g. gorilla glass, water resistance)
- Screen size, brightness and sensitivity
- User interface (e.g. how easy to select numbers/text accurately)
- Device size
- Global Positioning System (GPS) (particularly under forest canopy)
- Other functionality (e.g. camera quality, voice and video recording)
Battery life: besides the fact that the device may need to be used for a long period of time in the field and during interviews, the use of GPS and Bluetooth can quickly drain the battery of a phone. (Bluetooth is a wireless technology for exchanging data over short distances between devices, using short-wavelength radio transmissions.) Solutions include the use of solar-powered battery packs, spare batteries, or spare phones. Training can also help users understand when to turn GPS and Wi-Fi functions on and off to save power.
Memory: this is a key consideration, particularly when there is a need to use and save images, videos, audio files or maps as PDF files - and also when using software such as Open Data Kit, which may require forms and data to be stored on the phone itself (rather than on SD cards, which are interchangeable, allowing memory expansion).
Compatibility: software may only be compatible with certain mobile-based platforms such as Android, IOS, or Windows. For example Open Data Kit is currently only compatible with Android platforms.
Cost: this may be a deciding factor in how many devices can be bought for a project. It will need to be assessed alongside other criteria such as battery performance, screen size and ruggedness. For example, less robust phones may need to be replaced more often, and there could be extra costs if additional solutions are needed to boost battery power (see Battery life, above). Also, the cost of a device may vary depending on where it is purchased, due to different tax rates on imported technology.
Durability and robustness: if the devices are going to be used in an environment such as a tropical forest, they will need to be durable, robust and water proof. Check their Ingress Protection (IP) rating, which specifies the level of protection against environmental harm from solid objects, water, and shocks. Even phones with toughened glass can suffer in the field from cracked screens due to being dropped or crushed against hard surfaces when sitting. Purchasing additional protection is advisable. Waterproofing can be achieved using a protective wallet, rather than requiring it as a function of the phone, to allow other important functions to be maximised.
Screen size, brightness and sensitivity: smaller screen sizes may make data collection forms very difficult for monitors to use, however, larger screens come at a higher cost and the actual devices may be too large to carry easily. Brightness is vital to test in tropical forest environments where shade and bright sun offer contrasting challenges. Finally, sensitivity of the touch screen is important when considering how easy it is for users to enter data.
Operation and user interface: the device’s operating system and user interface will need to be appropriate for the people who will be doing the monitoring. If the device is too complex, it may need reprogramming to make it simpler to use; therefore it may make sense to choose a device which comes with a more user-friendly system. The operating system can also be adapted to limit its functionality to just what is needed for monitoring activities, and no more. This helps ensure that the phones (and their memory and batteries) are just used for the project, though this may also limit the benefits to the community, and therefore their interest in using them.
Device size: some devices may be too large or bulky to carry easily (this may be an important issue to consider for practitioners thinking about using tablets or specialised data logging devices). Smartphones are usually more compact and able to fit in a hand, pocket, or protective wallet.
GPS capability: the time taken to acquire a GPS location and the accuracy of the GPS function, especially under the forest canopy, may be a problem for some mobile phones. However, once acquired, their accuracy can be close to that of dedicated GPS devices, depending on the environment in which they are used. External Bluetooth GPS devices can help smartphones gain a location more quickly, but these can be expensive.
Other functions: additional functions worth considering include voice and video recording; measurement of distance (which can be installed as an app); and the ability to record areas as shapefiles. (Shapefiles are digital stores of information relating to geographical features such as rivers, roads, or land areas. They can describe lines, points or polygons, which can be used in geographical information systems, GIS.)