Nigeria - National Longitudinal Phone Survey 2021-2022, Phase 2

Start	End	Cycle
2021-11-29	2022-01-16	Baseline (Round 1)
2022-01-29	2022-02-14	Round 2
2022-03-26	2022-04-12	Round 3
2022-06-05	2022-06-20	Round 4
2022-07-30	2022-08-16	Round 5

Computer Assisted Telephone Interview [cati]
ORGANIZATION OF FIELDWORK: Data were collected by trained NBS interviewers who individually made phone calls either from a dedicated call center established in NBS headquarters or from their respective homes. Interviewers were allowed to make calls from home due to capacity constraints in the call center as well as social distancing measures undertaken in the office. While interviewers would occasionally meet in the office, most correspondence with the interviewers was made through WhatsApp, phone and emails.

GIFTS TO HOUSEHOLD: As a show of appreciation for the households’ participation, all households that gave consent to be interviewed, were transferred 1000 Naira credit to their phones (even if their interviews are only partially completed). The transfers are made to successfully interviewed households in every round. Since some of the sampled households do not have personal phone numbers, they were interviewed via a reference person’s phone. These reference persons were also credited 1000 Naira credit to their phones when the households are successfully interviewed via their phones.

PRE-LOADED INFORMATION: Basic information on every household was pre-loaded in the CATI assignments for each interviewer. The information was pre-loaded to (1) assist interviewers in calling and identifying the household and (2) ensure that each pre-loaded person is properly addressed and easily matched to the most recent interviews. Basic household information (location, household head name, phone number, etc.) was pre-loaded. The list of individuals from the previous interview and their basic characteristics were uploaded. This helped maintain the panel of individuals and ensured the status of each individual in the subsequent round of the survey.

RESPONDENTS: Each round of the Nigeria NLPS Phase 2 has ONE RESPONDENT per household. The respondent was the household head or a knowledgeable adult household member. The respondent must be a member of the household. Interviewers were instructed to make every effort to reach the same respondent in subsequent rounds of the survey, in order to maintain the consistency of the information collected. However, in cases where the previous respondent was not available, interviewers would identify another knowledgeable adult household member to interview.

DATA MONITORING AND EVALUATION: As an additional aid to ensuring good quality data, extensive monitoring was performed throughout the fieldwork for each round of the survey. Two monitoring exercises were implemented during data collection. First, Survey Solutions’ audio recording functionality was activated for 25 percent of the sample. These interview recordings were audited by 3 trained monitors, though not all recorded interviewers were able to be reviewed due to personnel constraints. On a daily basis, the monitors will listen to these recordings and fill in a structured questionnaire with their observations on interviewer performance. The feedback from these audio audits are then filtered to the respective interviewers.

The second quality check implemented were call backs to contacted households. The call backs were conducted by trained interviewers who are not part of the main data collection interviewers. Each day, up to 36 households that were contacted by the interviewing team are called by these call back interviewers. The call back interviewers conduct a short interview with the household to confirm that the interviewer did indeed conduct the interview, that certain key elements were clearly stated to the respondent, that the interviewer conducted themselves in a professional manner, and other details on the interview process. Further, the call back team asked several time-invariant questions of the respondent to further confirm the interview was fully conducted and the interviewer captured the information correctly. Feedback from call backs were routed to the respective interviewers to improve on identified areas. Further, the call back interviewers also called households that were not successfully contacted by the main interviewer. In some cases, the call back interviewer was able to reach the household. In such cases, the case was sent back to the interviewer to conduct the interview.

As a result of these quality checks, some of the interviewers were dropped from participating in the survey. There were also regular check-ins to address questions and issues the interviewers might have.