POPULATION AND SAMPLE

4.5.1 Population

According to Welman et al. (2005:52), the population is the study object and consists of individuals, groups, organisations, human products and events, or the conditions to which they are exposed. A research problem therefore relates to a specific

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population and the population encompasses the total collection of all units of analysis about which the researcher wishes to make specific conclusions. On the other hand, Sapsford and Jupp (2006:27) claim that the first step in sampling is to define the population of interest clearly and accurately. They define a population as the total collection of elements actually available for sampling. A useful discipline for the researcher is to bear firmly in mind precisely which elements were available in the intended population and which were not, and to use this information to limit the extent of the claims he/she makes about the generalisation of the results.

Springer (2010:100) claims that a population is the entire group of individuals that a study is intended to investigate. This author further states that the population of interest identified in a particular study is called the target population. In some cases, target populations are large, in others, target populations are relatively small. In addition, Ary et al. (2002:163) view a population as all members of any well-defined class of people, events or objects. For example, in a study where adolescents constitute the population of interest, you could define this population as all boys and girls within the age range of 12 – 21.

Similarly, Gay and Airasian (2003:102) argue that the first step in sampling is to define the population. They define the population as the group of interest to the researcher, the group to which the results of the study will ideally generalise. Populations may be virtually any size and may cover almost any geographical area. Also, the entire group the researcher would really like to generalise to is rarely available. The population that the researcher would ideally like to generalise to is referred to as the target population. The population that the researcher can realistically select from is referred to as the accessible or available population. In most studies, the chosen population is generally a realistic choice (e.g. accessible), not an idealistic one (i.e. target).

In the case of this study, the target population comprised 30 primary schools in the Uitenhage District of the DoE in the Eastern Cape Province. This is due to the fact that I was employed by the Uitenhage District of the DoE, and chose to work with the schools which formed part of that District.

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4.5.2 Sample

Miller and Salkind (2002:51) maintain that a sample is a set of research participants selected from a population. The goal of sampling is to select a sample where the sampling error (or difference between sample and population characteristics) is minimized. That way, the sample best represents the population of interest, and generalisability is maximised.

According to Teddlie and Tashakkori (2009:169), sampling involves selecting units of analysis (e.g. people, groups, artifacts, settings) in a manner that maximises the researcher‟s ability to answer research questions set forth in a study. The unit of analysis refers to the individual‟s case or group of cases that the researcher wants to express something about when the study is completed and is, therefore, the focus of all data collection efforts. In addition, Sapsford and Jupp (2006:27) are of the opinion that a sample is a set of elements selected in some way or another from a population. The aim of sampling, they claim, is to save time and effort, but also to obtain consistent and unbiased estimates of the population status in terms of what is being researched.

Sampling is the process of selecting a number of participants for a study in such a way that they represent the larger group from which they were selected. A sample comprises the individuals, items, or events selected from a larger group referred to as a population. If a quantitative sample is well selected, the research results based on it will be generalisable to the population. If a qualitative sample is well selected, it will likely focus on a limited group of articulate participants (Gay & Airasian, 2003:101-102).

Springer (2010:109-113) states that in qualitative research, sampling is informed by the ultimate goal of obtaining rich descriptions of people‟s beliefs, behaviours and experiences. Sample sizes, for instance, tend to be smaller than they are in quantitative studies. The information gathered from each participant in a qualitative study tends to be more extensive and requires more contact with the participants – in short, more information is collected from fewer participants. Qualitative sampling is often described as “purposeful”, because the goal is to deliberately identify

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individuals, organisations and/or materials that are informative. The approach to sampling on which a qualitative researcher ultimately relies, is determined by the research questions that either guide the design of the study or emerge during the gathering of information.

In having to decide on the type of sampling for this study, I opted for purposive sampling, as the literature guided me in regarding this type of sampling as appropriate for this study. In terms of purposive sampling, researchers handpick participants for a study, using their judgement to choose participants for the specific qualities they bring to the study. Purposive sampling can provide data that are more specific and directly relevant to a research concern or interest (Lankshear & Knobel, 2004:148-149). In addition, Gay and Airasian (2003:115) state that in purposive sampling, also referred to as judgement sampling, the researcher selects a sample based on his/her experience and knowledge of the group to be sampled, and identifies criteria for selecting the sample. Clear criteria provide a basis for describing and defending purposive samples. Much of the sampling in qualitative research is purposive.

According to Miller and Salkind (2002:53-54), in purposive or judgemental sampling, the researcher selects a subgroup of the population that, on the basis of available information, can be judged to be representative of the total population. Observations are then restricted to this subgroup and conclusions from the data obtained are generalised to the total population.

Springer (2010:107) describes purposive sampling as a procedure in which the researcher samples whoever he/she believes to be representative of a given population. This view is echoed by Ary et al. (2002:169), who add that the critical question in purposive sampling is the extent to which judgement can be relied on to arrive at a typical sample. The authors further state that because of its low cost and convenience, purposive sampling has been useful in attitude and opinion surveys, as mentioned in the previous section.

All the examples and/or definitions of purposive sampling cited in the body of literature consulted, strengthened my belief that purposive sampling was best suited

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to this study. The criteria for selecting a sample for this study were that the participant needed to be a primary school educator in the Uitenhage District and directly involved in CPD management. I firmly believe that the sample, which consisted of the IQMS coordinator at each of 12 primary schools in the Uitenhage District of the Eastern Cape DoE, would be representative of the whole population, namely all educators at primary schools in the Uitenhage District. The reason why I chose IQMS coordinators was, because as members of the SDT, they were directly involved with educators‟ CPD, as it formed part of their duties and responsibilities as IQMS coordinators. Using them as a sample would therefore suit my purpose to gain insight into and rich information on how educators were involved in their own CPD. The 12 primary schools chosen were all situated in relative close proximity to one another and to my workplace, thus saving time and money. I was also quite familiar with most of the participants, as my job entailed frequent interaction with them as representatives of their respective schools. In view of all this, I was convinced that purposive or judgemental sampling would be the most suitable choice for my study.