Top 9 Considerations When Choosing Tablets for Your CAPI Project
By Ofer Heijmans, CEO of Dooblo
The Market Research industry is transitioning from PAPI (Paper based surveys) to offline Tablet based CAPI. There are many factors to consider when making the transition to tablets, both hardware and software factors.
In this article I will focus on the tablets themselves and try to shed light on which of the hardware aspects are the most important to factor when choosing your devices and which can take a back seat if you are on a budget. You will be surprised how many low-mid range devices actually provide very good value-for-money and can in fact be used for 99% of the actual fieldwork that is done these days. The below is based on our experience at Dooblo where we help over 600 customers from 80 countries with the transition to CAPI using tablets and to perform over 20 million interviews each year.
1. Tablet sizes
Tablets come in different sizes ranging from the smaller 3.5” mini-tablets through 7” and 10” tablets. In general, the bigger the device the higher the cost but read carefully as for CAPI usage, bigger does not always mean better. The size you need highly depends on your unique CAPI environment and projects.
Our recommendation is that purchase a 7” tablet. The ideal blend of screen size, weight & costs makes it ideal for CAPI usage.
The amount of memory of the device is one of the most important factors for CAPI. The reason is that CAPI surveys tend to be very long and contain a hefty amount of complex logic. Due to the internal mechanisms of the Android operating system, even the most advanced tablet surveying apps like SurveyToGo require lots of memory. The reason is that typical questionnaires have tens if not hundreds of questions that need to be displayed along with media and many times some basic database access. All of these consume lots of memory.
We highly recommend purchasing a device with 1GB of memory or more. Try to stay away at all costs from devices with 512MB or less as you will be risking data integrity of your fieldwork.
GPS is very important for CAPI. The reason it is important is that GPS Locations of interviews and tracking interviewer routes is in 2016 a de-facto standard of quality control and without it you do not have the ability to know where a certain interview was performed nor where a certain interviewer walked around at a certain date-range. Luckily, today, almost all tablets are equipped with GPS however GPS is not a single yes/no parameter.
Make sure the tablet you choose has a true hardware GPS receiver. A-GPS and GLONASS should be considered as “nice-to-have” features.
While maybe initially the camera might not seem as an important concern, as you get more proficient with using tablets for CAPI the more important the cameras become from a Quality Control point of view. In today’s CAPI world, the camera is used both as a way for the interviewers to snap pictures of where they are right now, but also for the QC department to perform silent-photo-capturing to get a direct glimpse of the interviewer surroundings to confirm the fieldwork is done according to the highest standards.
Backward facing camera is a must. Specs are not important. If possible, get a device that also has a front-facing camera.
5. Battery power life
The battery within your tablet is responsible for providing “air” to your device so it can breathe. Since CAPI projects naturally are performed in the field, getting the most battery life out of your device is critical.
In general, device manufacturers state batteries can be re-charged 300-600 times before the end-of-life is reached, although in real-world use, this number is usually much higher. Battery capacity decreases considerably over time and recharge cycles, so even though a battery might last longer than 600 recharges, its capacity guaranteed to deteriorate over time. Average numbers state 20% loss in capacity after 250 recharges.
From your shortlisted devices, pay attention to the number of mAh and choose the one with the highest number. Keep in mind though that the #1 factor that will affect your battery is how you use the device and not the amount of mAh you have.
6. Screen quality
Why does screen quality matter? When thinking about CAPI work we often neglect this important aspect and while this aspect is less important than a few other critical ones, it is still an important aspect. The screen quality will affect both your battery consumption, how the screen is visible in the sun and how sharp & crisp videos and photos appear on the device.
If the majority of work is done in bright sun, get an IPS LCD screen. If majority of work involves showing videos or photos, insist on getting Full-HD screens and up. Otherwise, no special consideration is necessary.
While in CAPI the actual fieldwork take place while being completely offline, eventually the tablet will upload the data back to the data center and it will do so using its networking components. Different tablets have different components present and it is important to plan ahead and get the tablets that have the networking components you need. As networking components are relatively expensive it can have a real impact on the price you will pay for your tablet.
For most cases, WIFI is enough with Bluetooth being optional. If you foresee that you will need real-time data upload, make sure to get a device with a 3G or Cellular component even if you will not use it now, you might use it later.
8. CPU & Storage
CPU Speed and storage plays a big role when choosing a tablet for consumer use, however for tablet CAPI surveys this has almost no implications. Any CPU should run CAPI surveys fine, even the low end devices. As for storage, for surveys with no videos this has no implication at all as survey data output size measures in ~30KB in size while even the low-end devices these days have ~8GB of internal storage (not memory) available which essentially means you can store over 200,000 interviews on the device before the need to upload and free the space. The only exception for storage would be if you are capturing lots of videos or photos. Photos tend to be about 150KB in size and full-HD videos can quickly consume 3-5MB of storage space per second. So in case you are capturing a huge amount of photos or videos, you should definitely make sure the device has enough storage and potentially can be expanded with an external SD card based on your needs.
Do not worry about CPU speeds as they are not relevant to CAPI. Storage space should only be a concern in case you are capturing videos or huge amounts of photos, otherwise it is not a concern.
9. Android OS version
Do not worry about the Android OS version, just as long as your CAPI vendor supports the OS number your tablet runs. Before buying the device, check with the CAPI vendor to make sure the app supports the Android OS Number.
If you have any questions on tablet hardware for CAPI or which to consult on which tablet to choose for your projects, you are welcome to contact me personally at: email@example.com