Tablet Devices for Offline CAPI - Overview

Transcription

1 Tablet Devices for Offline CAPI - Overview For Customers Written by: Ofer Heijmans - Dooblo Page 1 of 6 2

2 Table of Contents 1 TABLET DEVICES FOR OFFLINE CAPI SURVEYS OVERVIEW TABLET SIZES SCREEN QUALITY CAMERAS BATTERY POWER MEMORY CPU STORAGE THE TABLET HARD DISK SEMI RUGGED DEVICE (3.7 ) POSSIBLE LOW-END DEVICES POSSIBLE MID-HIGH RANGE DEVICES... 6 Page 2 of 6 2

3 1 Tablet devices for offline CAPI surveys 1.1 Overview Android tablets come in all sizes and features. From very cheap low end devices to full featured expensive high end devices. The following will detail some possible options for low, mid & high end devices. Tablets vary mainly in the following: Size (3.5, 7, 10 and sizes in between) Screen quality GPS (yes/no) Cameras (No camera, forward facing or both forward and back facing) Battery power Storage CPU power 1.2 Tablet sizes There is a big distinction between the smaller 3.5 mini tablets and the other 7 + tablets. The mini tablets while being less expensive usually come equipped with both GPS and 2 cameras almost as a standard. However, for the larger tablets the availability of GPS and cameras is very dependent on price. It s therefore that if the project requirements can endure smaller 3.5 tablets, it will provide for better cost/benefits. For obvious reasons, smaller tablets will have smaller screens. 1.3 Internal Memory Important: Please do not confuse Memory with Storage. Some device vendors will list storage with descriptions that seem as if it is memory and confuse customers. Internal memory is one of the most important factors when choosing a device for tablet surveys. Complex surveys tend to use up memory and so it is generally not recommended to get a device with less than 1GB of memory. The following is a list of survey attributes that significantly increase the use of device memory: High quality images / videos High number of images / videos High number of quota definitions ( > 150) High number of questions ( > 100) Big answer lists for questions (> 300 answers) If you expect running surveys that will feature one or more of the above attributes Page 3 of 6 2

4 please consider to use a higher memory device. Following is a list of what would be considered low, medium or high memory devices: Low: > 500MB Medium: 1GB High: 1GB and up 1.4 GPS GPS is very important for CAPI as it forms the basis for quality control. SurveyToGo will use the GPS to capture location information to allow quality control and fieldwork departments to use this information to verify interviews were performed at the correct place. There are 2 different GPS types: 1. Hardware GPS: This is what most people refer to as GPS. This hardware receiver picks up the signal from satellites and determines the location with great accuracy and without the need for a WIFI or a 3g connection. It is present in most mid-high range devices and in some low-range devices. 2. A-GPS (Assisted GPS): This is a relatively new addition and this GPS will receive its location from either WIFI or 3g networks. Ideally, a device would have both hardware GPS and A-GPS which will allow the device to make out its location based on hardware GPS if possible and when not possible use the A-GPS instead. This is the case with almost all mid-high range devices. Some low-cost devices will have only the A-GPS and not a hardware GPS which means that if the device is not connected to the network no GPS location will be captured. It is not recommended to get a device with only A-GPS. 1.5 Screen quality When showing videos & photos, screen size and quality can make a big difference. 10 high-end devices will obviously provide the best combination of screen sizes and quality. However, smaller 7 devices are also adequate in size to display images and videos. As a rule of thumb, the lower end devices tend to have screens of less quality so if displaying media is a high priority screen quality should be given attention. 1.6 Cameras There are 2 types of cameras. Forward facing and backward facing. The forward facing camera is used in video conferencing to shoot the face of the person using the tablet. The backward facing camera is the one you use to take pictures of places. Usually, on the lower end tablets, either no camera is present or a forward facing camera only is present. If you need to take pictures of places/people on a regular Page 4 of 6 2

5 basis, it is advised to choose a device with a backward facing camera. 1.7 Battery power Battery power in tablets is affected from 3 main components: The battery size the bigger the better CPU strength the slower the better Screen size/usage the smaller the better, the less time the screen is on, the better. Battery power is as far as we know not directly related to the cost of the device. There are high end devices with small batteries and lower end ones with big batteries. 1.8 CPU CPU power plays a big role when choosing a tablet for consumer use as games and media rich applications eat up CPU making the device sluggish. When choosing a tablet for CAPI tablet surveys CPU power is less of an issue although for certain type of surveys you might want to consider more powerful CPU based tablets. Standard CAPI surveys of under 100 questions with little or no logic in them should run fine on any CPU. If you are planning to run surveys that contain the following attributes, you might want to use a faster CPU based device to prevent noticeable degraded performance that causes the device to seem sluggish: Lots of logic code and heavy use of functions Lots of Media (Videos, Images, Sounds) Querying big external data lists from inside the survey code > 50 quota definitions > 150 questions 1.9 Storage the tablet Hard disk Storage is usually not something you need to consider if you are planning on running tablet surveys that do not capture or make use of media such as videos, photos or sounds. If you are planning on capturing or displaying media, you should run some calculations to make sure the device storage is suitable for your needs. You need to take the following factors into consideration when doing the calculations: Size of media captured per interview Number of interviews before syncing (the media is removed after syncing). Page 5 of 6 2

6 1.10 Semi Rugged device (3.7 ) Device name Price Features Comment Motorola Defy Mini XT320 ~$ Possible low-end devices Device name Price Features Comments Archos 70 Internet Tablet 8 GB - $170 Android GHz Lenovo Ideapad A MU 7-Inch $199 Tablet ViewSonic ViewPad 7e 4 GB $170 ViewSonic ViewPad 10s 16 GB 1.12 Possible Mid-High range devices Device name Price Features Comment Samsung Galaxy Tab 7.0 $350 ViewSonic ViewPad 10s 16 GB $250 Motorola XOOM With Wi-Fi 32 GB $350 Acer ICONIA Tab A500-10S16u 16 GB ASUS Eee Pad Transformer TF GB Samsung Galaxy Tab 10.1 WiFi 16 GB $300- $400 $350 $350- $400 Page 6 of 6 2