Computer-Assisted Personal Interviews (CAPI)
Computer-Assisted Personal Interviews (CAPI) is a face-to-face data collection method in which the interviewer uses a tablet, mobile phone or a computer to record answers given during the interview. This page outlines the advantages and disadvantages of CAPI and provides points to consider when deciding whether or not CAPI fits well into your questionnaire programming and design plan.
- The wide variety of CAPI software makes it easy even for someone with no programming experience to program a CAPI questionnaire.
- CAPI helps to ensure high quality data by facilitating logic checks, skip patterns, validations, high frequency checks, and enumerator monitoring.
- CAPI relies on electricity, data or wifi connection, and tablets; the infrastructure and safety conditions of certain locations may not be compatible with CAPI use.
- CAPI facilitates logic checks, skip patterns, and validations during the interview. This makes the survey more efficient and helps assure higher quality data. It also saves later efforts on data cleaning and data entry.
- CAPI is a good tool to monitor enumerators. It can automatically record each interview’s start time, end time and GPS location, making it easy for supervisors to check whether an enumerator indeed conducted a given interview or not by comparing its time and GPS data to that of other interviews during which a supervisor was present.
- Given strong connection to wifi or data, data collected by CAPI surveys is immediately uploaded in an electronic format. This allows the research team to run high frequency checks.
- CAPI surveys may be difficult to conduct in crime-ridden areas, since tablets or phones are easy targets for thieves. In these cases, PAPI or CAFE surveys may have a comparative advantage.
- CAPI relies largely on electricity or data connectivity, which may not be feasible in some remote parts of the world. If CAPI data gets corrupted before it is uploaded to a server, it is lost forever. Battery packs and offline data storage can certainly facilitate CAPI surveys in regions without good electricity or data connectivity; however, PAPI may be the best option in these cases.
- Relative to PAPI, CAPI less effectively collects data in interviews that entail many comments or qualitative information (i.e. qualitative surveys, survey pilots, etc).
- Some respondents are not comfortable during CAPI surveys due to concerns unauthorized access to personal data. This may result in either no data from such respondents or low-quality data due to a lack of trust. Therefore, research teams should take adequate steps to resolve these concerns.
- CAPI surveys require technologically competent enumerators or longer training periods for enumerators. This may pose a problem for surveys conducted in emergency or last-minute situations.
DIME most commonly uses SurveyCTO, an Open Data Kit platform, for CAPI surveys. Other CAPI software commonly used in data collection is listed in the table below.
|CSPro||United States Census Bureau|
|Dooblo||Dooblo Ltd., Israel|
|Open Data Kit(ODK)||University of Washington's Department of Computer Science and Engineering|
|SurveyBe||Economic Development Initiatives Limited, UK|
|SurveySolutions||The World Bank|
When choosing a CAPI software, consider the following factors:
- Data capture: does the software capture all forms of data that you need (i.e. text, numbers, pictures, audio, etc.)? Does it have the language support that you need to conduct multilingual surveys or record multilingual answers ?
- Questionnaire navigation: is it easy to navigate through the questionnaire in the software? Can you perform the skips and loops that you need to do in your survey in the software ?
- Data quality control: does the CAPI software provide ways of controlling data quality (values within certain range, values with a required character, values without a certain character, etc.)?
- Data management: is the data output file from the CAPI Software compatible with the statistical tool you use to analyze datasets?
- Case management: does the software facilitate management of tasks for various people within the impact evaluation team during a survey?
When choosing a tablet to use with CAPI software, consider the following factors:
- Wifi and cellular connectivity: preferably the tablet can connect to a network with widespread 4G coverage throughout the survey territory.
- Front and back cameras: the cheapest tablet models have only front cameras, but if you need pictures of anything, these won’t work well.
- Up-to-date Android operating system: the current fully-supported versions are marshmallow and nougat.
- Size: the ideal size of your tablet depends on your questionnaire design and complexity. 7 inches is typically fine, though if your questionnaire includes a lot of tables, you may want to use 10 inch tablets. On the other hand, if your questionnaire is very simple, a 3.5 inch tablet may be sufficient.
- Internal storage: aim for at least 1 GB memory. If the survey is particularly complex or you are implementing multiple questionnaires simultaneously, you may need more than 1 GB. You may also consider using tablets with SD card capacity to expand available memory.
- Screen: if you need to show videos or photos to respondents, consider a HD screen. It not, no special screen considerations are needed.
- GPS: your tablet should have GPS capacity in order to assure high quality data and monitor enumerators. However, GPS is typically pretty poor: it may take a long time to lock on to a signal and only offer an accuracy of 10-15 meters. Bluetooth receivers (i.e. GlobalSat BT-821 Bluetooth GPS Receiver) can help to enhance GPS capacity.
- Font and language requirement: if you’re working in a place with a non-Roman alphabet, make sure that’s supported.
- Battery life: how long can your tablet last in the field before it needs to be recharged?
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This article is part of the topic Preparing for Data Collection
- The World Bank's Comparative Assessment Study of CAPI Software
- World Bank slides on CAPI
- Cayers, Chalmers and Weerdt's randomized survey experiment comparing CAPI and PAPI survey methods
- IPL's Low-Cost, Automated WhatsApp Surveys
- T Hlaka's How to responsibly collect or acquire data for M&E