Supervision
The mobile tracking team consisted of one supervisor, two interviewers, one data entry
technician, and one driver. In addition, there were two dedicated tracking enumerators that
remained in Dar es Salaam. The tracking team began interviews three months after the
beginning of fieldwork to allow enough time to accumulate a sufficient number of tracking
targets. Tracking targets were grouped into geographic regions, and the team would visit the
regions approximately every 2-3 months. Any tracking target not located was remained in the
pool to be visited during the next trip, in addition to any new tracking cases that had accumulated
in the intervening months. In addition, the regular field teams also sporadically would perform
tracking within their interview regions if there was a backlog of cases. Finally, following the
completion of the main fieldwork activities, four supervisors led dedicated tracking teams to
interview the remaining cases.
Data Collection Notes
The survey was implemented by eight mobile field teams, each composed of: one supervisor, four enumerators, one data entry technician, and one driver.
The teams visited each enumeration area for between 4-5 days. The questionnaires were administered to the selected households over the course of that time. This allowed the field team to make return visits to the household to complete the entire Household questionnaire and, for farm households, Agriculture questionnaires, and for Fishery questionnaires. To ensure the depth and quality of each section of the survey, the questionnaire was administered across multiple respondents to the most knowledgeable about each topic. For all of the sampled 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 1 hour from the
location of the household. Anthropometric measurements were taken for all individuals that were
at home, not too ill, and willing to participate
If the field teams enter an enumeration area and find that the entire household or a member(s) of the household has moved, they are required to follow the tracking protocol. If the entire household has moved from the original residence, teams are required to fill a T-1 form. The T-1 form contains information on the new location of the household, allowing for the teams to locate and interview the household members. If a member or members of the household have split from the original household, a T-2 form is filled out by the teams. Similar to the T-1, a T-2 form contains information on the location of the member(s) who have split from the household. Once the tracking targets have been found, teams are required to interview them and any new additions to the household. Out of the tracking individuals/households, only those over 15 years of age are included in the tracking protocol unless an individual under 15 years of age moved with another individual over 15 years of age, and both were part of the round one data collection
Within the tracking protocol, there are local and distance cases. Local and distance tracking applies to both T-1 and T-2 forms. Local tracking occurred when the tracking target is within one hour traveling distance from the original EA and at least one tracking member from the household is over 15 years of age. If that is the case, the teams are required to interview the tracking target before leaving the original EA. Distance tracking occurs when the tracking target is not within one hour traveling distance from the original EA. In this case, the teams fill out the appropriate tracking form and send the information NBS headquarters. Once at NBS, the distance tracking case is given to the tracking team, who is then responsible for locating that household and conducting the interview.
The mobile tracking team consisted of one supervisor, two interviewers, one data entry technician, and one driver. In addition, there were two dedicated tracking enumerators that remained in Dar es Salaam. The tracking team began interviews three months after the beginning of fieldwork to allow enough time to accumulate a sufficient number of tracking targets. Tracking targets were grouped into geographic regions, and the team would visit the regions approximately every 2-3 months. Any tracking target not located was remained in the pool to be visited during the next trip, in addition to any new tracking cases that had accumulated in the intervening months. In addition, the regular field teams also sporadically would perform
tracking within their interview regions if there was a backlog of cases. Finally, following the completion of the main fieldwork activities, four supervisors led dedicated tracking teams to interview the remaining cases.
Data entry was done concurrently with data collection by the data entry technician, using a laptop, known as first data entry. The data entry program was a CSPro-based system, developed by NBS with support from the World Bank. This facilitated the performance of internal crosschecks prior to departure from the enumeration area, allowing enumerators to return to households and clarify inconsistent information on the questionnaires. Data files from completed EAs were then e-mailed to headquarters using 3G modems. These files were
concatenated and periodic checks were done to ensure the fieldwork was proceeding according to the calendar. The field teams also send the paper questionnaires back to the headquarters on a monthly basis.
Once the paper questionnaires and data files for completed EAs were received at NBS headquarters, a double entry procedure was implemented. Eight data entrants were hired by NBS to re-enter the data from the paper questionnaires into the CSPro-based data entry system for all households and questionnaires administered. A cross comparison between the entered values in the field based data entry and double entry was conducted and any differences in values between the two were flagged for manual inspection of the physical questionnaire. Corrections based on this inspection exercise were ultimately encoded in the dataset.
Additionally, an extensive review of data files was conducted, including interviewer errors such as missing values, ranges and outliers. Observations were returned for manual inspection of the physical questionnaires if continuous values fell outside five standard deviations of the mean, categorical values were not eligible responses, or there were internal inconsistencies within the dataset (for example, the age of an individual was not consistent with their educational status, there was more than one head of household listed, an individual was engaged in multiple primary activities, the quantity of crops and their byproducts produced, harvested, and sold not listed, the distance from the market and an individual’s plot was not listed, the number of weeks, days per week, and hours per day an individual engaged in fishery activity was not recorded, the species and quantity of fish caught, bought, sold, or traded was not listed, etc).
When it was determined that these values were the result of data-entry error, the values were corrected. In addition, cases deemed to reflect obvious enumerator error were also corrected in this cleaning process. The majority of such cases involved the use of incorrect measurement units, e.g. recording grams as kilograms or vice versa.
