viewed to be close to or completely exhaustive. The list contained the GPS location and information on type of water point (Berkad, Borehole, Dam, Dug Well, Spring, Other). Other water point characteristics such as the number of households using the water point and the predominant type of cattle watered were available only for an incomplete subset of water points. The list was stratified implicitly by pre‐war region (each federated member state encompasses several pre‐war regions) and type of water point.

## _First‐stage sample selection_

Water points from this list served as primary sampling units. In the absence of reliable estimates of the population size of water points, 42 water points were selected in the first stage with equal probability, with 12 interviews to be conducted at each selected water point. A further challenge in sampling nomadic household peculiar to the timing of SHFS wave 2 was the ongoing drought, which led to many water points having run dry. Therefore, a series of Key Informant Interviews (KIIs) and Focus Group Discussions (FGDs) in each federated member state verified whether each selected water point was currently frequented by nomadic households. In case a selected water point was not currently frequented by nomadic households, it was replaced.

## _Selection of nomadic households at water points_

Selection of nomadic households to interview relied on a listing process at each water point whose aim was to compile an exhaustive list of all nomadic households at the water point. However, the total number of nomadic households at a given water point is not static as nomadic households are not resident at water points, but only stay there for a limited time, and arrive and leave at various times during the day. It was determined in KIIs that nomadic households need to spend a very minimum of two hours at a given water point to water their cattle and that cattle watering would occur during daylight hours. To allow for a complete listing, daylight hours were segmented into two‐hour time slots, during each of which enumeration team leaders completed a full listing of all nomadic households at the water point at that time. As not all persons present at water points were members of nomadic households, but may instead be from close‐by rural settlements, the listing form contained a number of questions identifying nomadic households. The form also asked for informed consent to be interviewed. Upon completing a two‐hour listing period, up to three households were randomly selected from the list of consenting nomadic households gathered during this time slot. Interviews were then scheduled with the selected households at a time and place convenient for the household respondent.<sup>4</sup> Based on this sampling design, sampling weights were calculated after the completion of data collection (see Appendix for the derivation Sampling weights).

# 3. Data collection

Wave 2 of the Somali High Frequency Survey was implemented using computer assisted personal interviewing (CAPI), whereby enumerators were equipped with tablet computers which contained the survey questionnaire (section 3.1) and would upload completed interviews to the project’s Survey 4 Additional rules applied in special cases: (i) If no nomadic households were found or arrived at a given water point, enumeration teams remained at the water point for three days. If no nomadic household had arrived, the water point was replaced. (ii) If nomadic households were present but arrived at very low frequencies, so that teams struggled to reach the required number of interviews, they would stay for a maximum of 12 days. Then teams would leave whether or not they have reached the required number of interviews. If 3 or fewer (but at least 1) nomadic households arrived during any two‐hour listing period, all listed households were interviewed during that period.

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