National Panel Survey 2020-2021, Round 5

Preparations:

The main training for the field team supervisors and enumerators took place in the Iringa region between November and December 2020 over a period of thirty days. During this time, the field staff spent one week on the Household Questionnaire, a week on the Agricultural Questionnaire, and a week on the Livestock Questionnaire and tracking forms. The last week of training was devoted to field practice. Field practice was conducted in Iringa region, where selected households from the previous rounds of the NPS were revisited to provide enumerators and supervisors with practice in conducting tracking during fieldwork. After the fieldwork, extensive discussion and revisions were conducted with the participation of all team supervisors.

Over the training period, three tests were administered to the field teams. The goal was to gain feedback from the training sessions and to select qualified enumerators. There were 54 enumerator candidates, and all were selected. Manuals for the interviewers were developed with detailed instructions for field staff during training and as the main reference guide for the survey over the course of fieldwork. At the end of the training, each enumerator was provided with an interviewer manual in Kiswahili.

Field Work:

Fieldwork for the NPS 2020-2021 began in the last week of December 2020 and was completed in January 2022. This 14-month span of fieldwork addresses any intra-year seasonality concerns and fluctuations. The survey was primarily implemented by eight mobile field teams, each composed of one supervisor, seven enumerators, and one driver. Seven mobile field teams were responsible for different regions on the mainland, and one team was responsible for all of Zanzibar.

Field teams visited each cluster for 2-3 days for both panel and booster clusters. The questionnaires were administered to the selected households over the course of that time. This allowed the field team to make return visits to households to complete the Household Questionnaire, the Agriculture Questionnaire for farming households, and the Livestock Questionnaire for households engaged in livestock activities. To ensure the depth and quality of each section of the survey, the questionnaire was administered to multiple respondents and to the household members most knowledgeable about each topic. For all the sampled tracking households, areas of all owned and/or cultivated agricultural plots were measured via GPS unless the household refused, the terrain was too difficult, or if the plot was more than a one hour drive from the location of the household. Anthropometric measurements were taken for all eligible individuals who were at home, not too ill, and willing to participate.

Tracking:

Tracking consisted of three stages:

1. determining the current status of the households and their members from the previous survey
2. determining the location of any households that have moved together with all their members to a new location
3. determining the location of any eligible members who have moved from their household in one or more rounds of the NPS to a new location

Eligibility of households and members for tracking was determined prior to the implementation of the survey. Members eligible for tracking were those over the age of 15 and who were not a live-in house servant. Any members not meeting this criterion were not tracked, and they were only included in the data when located and interviewed with an eligible member. Furthermore, households eligible for tracking had to have moved to a new location within Tanzania. If a household moved to a different country, it was not tracked.

If an entire household had moved from the original residence, teams were required to complete a “T-1” form designed to capture relevant information from key informants on the whereabouts of the household. The T-1 form contains information that would enable tracking of the household to its new location. If one or more members of the household had moved from the original household, a “T-2” form was completed by the teams. Similar to the T-1 form, a T-2 form contains information on the location of the member(s) who have moved from the household. Once the tracking targets had been located, teams were required to interview the household in accordance with the eligibility requirements.

Within the tracking protocol, tracking cases are differentiated into local and distance tracking. Local and distance tracking apply to both households and individuals. Local tracking is defined as cases where the tracking target is within one hour driving distance from the original cluster, and at least one tracking member from the household is eligible for tracking. For local tracking cases, the teams are required to interview the tracking target before leaving the original cluster. Distance tracking occurs when the tracking target resides in a location that is more than one hour drive from the original cluster. In this case, the teams fill out the appropriate tracking form and send the information to the Tanzania National Bureau of Statistics (NBS) headquarters. Once at NBS headquarters, the distance tracking case is given to one of the field teams based on the location of the new residence of the household or individual. This assigned field team is then responsible for locating that household and conducting the interview.

Often households and members who have moved from their previous dwelling or household have relocated at a great distance from their previous interview location. Given the inefficiency of searching for these members on a case-by-case basis across the country as they occur, field teams were not required to track households and members deemed to be too far away from the original location. Information on these cases was entered and sent electronically to the NBS headquarters for compilation and review. After review, the tracking cases were assigned to the field teams based on the location of the new residence of the household or individual.

Distance tracking was performed after the completion of the main data collection to allow enough time to accumulate a sufficient number of distance tracking targets. Furthermore, regular field teams would perform distance tracking whenever they had a break in their schedule. Three dedicated teams of four enumerators conducted the distance tracking fieldwork.

Data Processing and Management:

The NPS 2020-2021 contains a robust multi-level quality assurance and data management system. Great efforts were devoted to the development and utilization of this system by the NBS with technical assistance from the World Bank prior to the implementation of the NPS 2020-2021 to assist in the management of the complex household panel survey and address the growing need for high-quality timely data.

The NPS 2020-2021 utilized a Survey Solutions Computer Assisted Personal Interviewing (CAPI) system developed by the World Bank in collaboration with IT personnel from NBS. This system was selected to increase the availability of data for review by managing staff as well as to provide regular and consistent quality assessment of the data directly to the field staff. STATA software was utilized to perform complex aggregated checks. Furthermore, due to the panel nature of the survey, data was checked against previous round data, where applicable and appropriate.

Data files from completed clusters were transmitted to NBS headquarters via syncing to the Survey Solutions server using 3G USB modems. The received data files were downloaded at the headquarters, and regular checks were performed to ensure the fieldwork was proceeding according to the schedule and that quality standards were met. During the course of fieldwork, data was routinely checked at the aggregate level to identify any potential issues and in such cases additional checks were integrated into the CAPI and Stata systems.

Throughout the data processing, system versions of the data were archived at all key steps and all checking and cleaning syntax were documented and archived.