Selection criteria and sampling methods

A ‘Child’ was defined according to the United Nations Convention on the Rights of the Child (CAC) as a ‘human being below the age of eighteen years’ (UNICEF, 1989). All children carrying adult responsibilities (as defined by the children themselves) were eligible for the qualitative study. Adult community members of all ages and national and international staff of service providers who were either permanently based in Akobo or supervising projects in Akobo were invited to participate in the case study. Resident and displaced populations were included. As most people were displaced at some point in time during the civil war, being a resident was defined as having lived in the same place at least since the CPA in 2005. Stratification of the population into homogenous groups was done by age, gender, resident population, displaced population, members of the ‘White Army’ (militia group), children under parental responsibility, orphans and half orphans, and married girls. This approach aimed at covering the population and the different views and experiences of adults and children as broadly as possible.

The mental health survey included IDP children aged 12-18 from the 19,000 people displaced by the Nyandit attack in April 2009. This population was chosen because they had settled in locations that were accessible and not considered ‘off limits’ by the Save the Children in South Sudan (SCiSS) security advisor and the SSRRC. Of the 19,000 people displaced approximately 3000 had crossed border into Ethiopia and were excluded from this study. Data were collected in three different locations where the 16,000 displaced persons from Nyandit Payam had settled. One group of IDPs (estimated population 9,000) lived among the resident population of Akobo town; another group (estimated population 4,000) lived in an

Theory Hypothesis Observation Confirmation Theory Tentative Hypothesis Pattern Observation

IDP camp close to Akobo town and a third group (estimated population 3,000) had returned to Nyandit Payam.

4.3.1. Study area

All investigations reported in this study took place in Bilkey Payam with four Bomas: Akobo town, Dima, Old Akobo and Dilule, and in Nyandit Payam with the four Bomas: Mer, Padide, Chibang and Obor. The two Payams belong to Akobo East County. Figure 4.3 shows the approximate research area.

Figure 4.3: Approximate research area in Akobo County

4.3.2. Sampling methods: qualitative

Three non-probability sampling techniques were used in the selection of the study respondents. They included purposive or judgement sampling, quota sampling and snowball sampling.

Purposive or judgemental sampling is mainly used in the selection of ‘information rich’ respondents who are able to provide an in-depth understanding of the area or the population under investigation. Purposive sampling differs from quota sampling in that there is no overall sampling design indicating how many of each type of informant is needed (Bernard, 2000:176). Respondents may be regarded as ‘information rich’ if they have extensive knowledge about particular groups of people or about a particular behaviour, experience or phenomenon under investigation. Most purposive samples are small (Bernard, 2000:178). In this research purposive sampling was used in the selection of key informants and health service providers.

Quota sampling is mainly used in the selection of subpopulations of interest and the proportions of those subpopulations in the final sample. Quota sampling resembles stratified probability sampling with the important difference that the respondents are not chosen randomly but by the investigator on the spot (Bernard, 2000:175). In this research quota sampling was used in the selection of children and adult community members to account for the heterogeneity in a population by obtaining representatives of the various subgroups.

Snowball sampling is mainly used in studies of social networks with the objective to find out who people know and how they know each other. It is also used in studies of ‘difficult to find populations or population groups’ (Robson, 1999:142). In this research snowball sampling was used for ‘difficult-to-find’ groups: orphans and half- orphans, married girls, and members of the ‘White Army’. The starting point in each group was an already sampled respondent who selected people they knew who fitted the selection criteria.

4.3.3. Sampling methods: cross sectional survey

Random sampling is used in quantitative research to obtain an unbiased sample, although this can be problematic in situations where no sampling frames are available (Bernard, 2000:147). A sampling frame is a list of units of analysis from which a sample is taken in a way that each unit, for example an individual person, has exactly the same chance as any other unit of being selected. This is a considered by many researchers as being a precondition for a sample to be truly representative and to allow for generalisation (Bernard, 2000:147). In many settings (including those pertaining for the study reported in this dissertation), however, these requirements for representative sampling are very difficult, if not impossible, to fulfil (Robson, 1999:142-144). For this study, therefore, a modified systematic random sampling approach was used because no sampling frame was available; this was based around the ‘spin the bottle’ technique suggested by WHO in the Expanded Program of Immunisation (EPI) manual (WHO, 1991) because no household lists were available to randomly select a starting point.