Sri Lanka census department switches to computerized surveys after pilot study
ECONOMYNEXT- The Census and Statistics Department (DCS) has adopted a new computerized interviewing system, which has reduced errors and costs of national surveys following a pilot study, a report said.
“Shifting the way of collection of public data from traditional Pen and Paper Interviewing (PAPI) to Computer-Assisted Personal Interviewing (CAPI) was the heaviest advancement made by the DCS,” the department report said.
“Currently most of the national surveys including the Census of Population and Housing 2021, conducted by the DCS are successfully being conducted or all set to be conducted using CAPI on mobile devices such as smart phones and/or tablet computers.”
The first CAPI survey was conducted as a pilot for the Sri Lanka Agriculture Household Survey 2016/17 using physical, technical and financial support from the Asian Development Bank, DCS said.
While the national survey of 25,000 households was done with PAPI, a separate CAPI survey was conducted on 2,000 households in the Anuradhapura District to compare results.
CAPI surveys remove the need to print large reams of paper and carry them, therefore reducing both printing and labour costs, DCS said.
Inputting data from paper to computer systems is also eliminated, reducing costs and errors.
“Currently, CAPI variable costs at 0.57 US dollars per interview is already 11 times less expensive than PAPI at 6.30 US dollars per interview.”
“Thereby, CAPI is more cost-effective than PAPI especially for medium to large-scale surveys.”
Missing data, which is the most common error, fell by 90 percent in a simpler household CAPI survey compared to PAPI surveys, while for a more complex survey done on the agriculture sector workers showed a 50 percent fall in errors with CAPI.
This was due to computerized checks on missing data fields and automated skips when questions are not relevant to the person being interviewed.
Inaccuracies were also reduced as CAPI surveys are programmed to check for logic in answers, DCS said.
Interviewers are able to focus more on communication with the respondents due to error checking built into CAPI surveys.
CAPI also increases quality of surveys due to the possibility of adding features as capturing photos and videos, recording audio and gathering GPS information.
“These features are not possible in PAPI Surveys,” DCS said.
The report said CAPI has higher fixed costs due to software and handheld device acquisition, and programming costs, although this is offset by its lower variable costs.
“Cost should not impede future scale up of CAPI.”
“Current trends suggest that fixed costs will also decline due to availability of more low-cost and easy-to-learn CAPI software options that will greatly reduce programming and design expenses.”
“Additionally, digital devices will also continue to become more affordable thus also reducing variable costs.”
“Overall, CAPI will greatly benefit the DCS.” (Colombo/ Dec 6/ 2019)