What is an offline survey?
Offline survey definition
Offline surveys are conducted face to face using tools that allow data collection even when Internet access is unavailable.
In survey research, this approach is commonly known as the CAPI methodology (Computer-Assisted Personal Interviewing). With CAPI, an interviewer conducts the survey face to face rather than over the phone or online.
Because interviews often take place in locations where Internet access may be limited or unavailable, the survey software must be capable of operating offline. This allows interviewers to collect data reliably in rural areas, remote locations, or any environment without a stable mobile or Wi-Fi connection.
Data collection is typically carried out through a mobile app running on a tablet or smartphone, although laptops may also be used in some cases. Responses are stored locally on the device and automatically synchronized with the central database once an Internet connection becomes available, such as at the end of the working day.
Why to use an offline survey
Data capture on mobile devices and syncing results when connection is available
An offline survey is the ideal methodology for two scenarios:
- Interviewers recruit people to be interviewed at specific locations, such as shopping malls, stores, car dealerships, trade fairs, hospitals, or any other location where people on target with the survey purposes can be found.
- Interviewers are assigned specific contacts, go to their home or workplace to conduct a face-to-face survey. For example, to interview doctors at their offices, families at their homes, etc.
Offline survey tools can be adapted to a variety of research scenarios and customized to fit the specific needs of each survey project.
How offline surveys differ from online surveys
Offline surveys vs other data collection methods
| Method | Best for | Main advantage | Main limitation |
|---|---|---|---|
| Offline surveys | Field interviews, audits, low-connectivity environments | Data can be collected without internet | Requires sync later |
| Online surveys CAWI | Broad digital audiences Web-based self-completion | Fast and scalable Low cost and easy distribution | Needs internet access Lower control over context |
| CATI | Structured phone interviews | Good interviewer control | Higher operational cost |
How to choose the best survey software for face to face interviews
The choice of the right survey software for face to face interviews is crucial. Here are the most important features to consider when you choose the CAPI survey software.
APPs for offline survey
Not all survey software provides a solution for conducting face-to-face surveys, and even fewer offer offline capabilities. Be sure that the survey software you selected includes both these features and a dedicated APP for these purposes.
Compatible APP with all mobile devices
The APP must be compatible with the most common devices, such as smartphones and tablets, both Android and Apple, regardless of their OS version.
Choosing a tool that offers an APP compatible with the most popular devices brings many advantages, such as the possibility of using interviewer-owned devices, or low-cost devices provided by the agency or organization conducting the research without offline survey.
APP you can download from Google Play or AppStore
Interviewers can independently download the APP to their own devices, eliminating the need to deploy pre-configured tablets or smartphones. This solution lowers costs as no investment is required to purchase dedicated devices.
Easy setup and good usability of the APP
When working with interviewers scattered throughout the territory, assisting them can become complicated and onerous. It is essential that the APP is easy to install and that the download of the questionnaire, the data collection, and the data synchronization are simple, even for interviewers not previously trained.
Geolocation and background audio recording
The app must record the GPS location of each interview and background audio recording to allow supervisors to verify the authenticity of the interviews conducted.
Costs and sales model of the software
Some software charge for each face-to-face agent in addition to the main cost of the system.
This does not allow for a scalable cost since the number of agents may change from project to project, or face-to-face survey projects can be sporadic, making the initial investment unjustified.
Other software charge for the respondents’ APP. This is the most inconvenient solution as it complicates the download of the app.
Other software, such as IdSurvey, has a cost by completed interview and offer the offline survey APP for free. This solution allows a scalable solution with no fixed costs. In the case of IdSurvey, there are also no costs for the main interface.
Mixed-mode surveys
When mixed-mode is best
CAPI methodology can often be used in conjunction with other methodologies, for example the CATI methodology (phone surveys) or CAWI methodology (online surveys). For example, interviewers may first contact respondents by phone (using the CATI methodology) to schedule an appointment and then conduct the survey in person at a later time.
Alternatively, field interviewers can recruit participants face to face, collect their contact information, and send them a survey link via email or SMS, allowing them to complete the questionnaire independently using the CAWI methodology.
