Digital vs. Paper

Computer Assisted Personal Interviewing (CAPI) and Paper and Pencil Interviewing (PAPI) are two different methods of conducting surveys and collecting data.

PAPI is the traditional method in which an enumerator fills in a paper form or questionnaire. With CAPI, the enumerator uses a tablet, smartphone, or laptop computer to move through the interview and record responses.

We're big fans of digital methods because we think they get you better data faster and more cost-effectively – but as a digital technology provider, we're obviously biased. To more objectively outline the opportunities (and costs!) of going digital, we've created a table to compare the methods and we've adapted two additional tables from Oxfam's Effectiveness Review.

Comparing methods

TEMPLATE DESIGN A data-collection template needs to be designed before data collection can begin. This template will be loaded onto the devices data collectors use in the field, and the data will be recorded directly from the interview onto the device. Physical survey forms must be designed before data collection can begin; a data-entry template needs to be designed before data from the paper surveys can be entered into a computer. The template will define each variable or question, specify what entries are valid, and indicate which fields should be skipped under which circumstances. This is often done after the survey has already launched.
QUESTION TYPES Forms can allow multiple-choice and write-in responses; they can also capture the current GPS location, take photos, record audio or video, perform calculations, capture signatures, allow respondents to draw onto photos, and more. Forms can allow both multiple-choice and write-in responses. They can also allow spaces for the respondent to sign or draw directly onto the form.
HARDWARE Smartphones, tablets, laptops, or netbooks will be needed for each of the data collectors to perform interviews and record responses. Hardware is one of the key costs in digital data collection.

Computers will be needed for data entry. If the project will do in-field data entry, laptops or netbooks will be needed.
SOFTWARE Different software options are available. Pricing, programming difficulty, support, and flexibility vary widely. Data-entry software will be needed. Some options are available at no cost (e.g., CSPro), while others are not (e.g., Microsoft Access).
PRINTING No printing is required for a CAPI survey. Paper-based survey forms must be printed. And, if they are printed in bulk and then revisions are later required (a common situation), stickers or replacement pages may need to be printed and then inserted into existing forms. Printing is one of the key costs in paper data collection.
ENUMERATOR TRAINING Since skip patterns and field validation are handled by the data-collection device, enumerators can be trained more quickly. However, those not used to using smartphone or tablet technology may need extra time to become comfortable using the devices. Complex or numerous skip patterns can be difficult for enumerators to master, and it may take much practice for enumerators to reliably enter valid responses into all fields. Therefore, the necessary training period could be lengthy.
TRANSPORTATION AND STORAGE Surveys are typically "transported" via USB connection, local wi-fi network, or the internet, then "stored" on a server or local hard drive. Proper precautions must be taken (generally using data encryption) to ensure that the data is secure both in transit and, to the greatest extent possible, at rest. A secure system must be designed to bring the surveys from the field to the office, and to store the surveys in the office. Once data is entered into the computer, it should be stored securely (generally using data encryption).
DATA ENTRY The data is instantly digitized as it is entered into the tablet. Data must be entered into the programmed template by trained data-entry operators. For each form or questionnaire, typically two entries are completed, they are compared, and any differences between the two are corrected. Data can be entered in the field if laptops or other mobile hardware are available and the data-entry operators are able to travel. The advantage of in-field entry is that the data is available faster for scrutiny, allowing errors to be caught while the team is still in the field. Data entry is one of the key costs in paper data collection.
QUALITY CONTROL The flow of questions is automated, so the enumerator does not need to decide which question comes next; it is calculated by the phone or tablet. Many other quality control measures are possible with CAPI, such as logical checks, pre-filling information, setting constraints on answer ranges, and secretly recording audio for later review. The data is also available right away in a digitized format to look for any other problems. Typically the survey team will include "scrutinizers", whose job it is to look carefully at the completed questionnaires and catch enumerator errors. The questionnaire can then be sent back to the field for correction.
DATA CLEANING The data cleaning process can begin after the first day of surveying. At this time the enumerators are still able to return to any household if they need to make a correction. Once the data entry is complete, the cleaning process can begin.
TIME TO DATA In the typical set-up where field teams securely upload data to a server on a nightly basis, data is available by day two of data collection. Data typically becomes available only after all of it has been entered and cleaned. This can be weeks or months after the actual data collection.

Comparing processes

Questionnaire design Questionnaire design
Coding digital questionnaire  
Piloting and testing Piloting
Training (digital and paper) Training (paper)
Survey data collection Survey data collection
Monitor data quality  
Community feedback summary statistics  
  Data entry
Data analysis Data analysis

Adapted from Oxfam's Effectiveness Review of SurveyCTO.

Comparing costs

SOFTWARE $99* $0 + $99
PRINTING $60 (20% budgeted for backup) $300 - $240
DATA ENTRY $210 (10% budgeted for backup) $2,100 (approx. cost of 4 data-entry clerks & 1 supervisor for 15 days) - $1,890
TOTAL (EXC. HARDWARE) $369 $2,400 - $2,031
HARDWARE $1,000 (based on 10 devices at $100/device) $0 + $1,000
TOTAL (INC. HARDWARE) $1,369 $2,400 - $1,031

Adapted from Oxfam's Effectiveness Review of SurveyCTO. We changed the currency to U.S. dollars, updated the software cost to reflect our $99 professional plan (versus £162 in the original table), and revised the projected hardware cost to $100/unit (versus £300 in the original table).

* Software cost: additional savings when more than one survey runs in the same month.