THE RESEARCH POPULATION, THE RESEARCH SAMPLE AND THE SAMPLING

A description of the linkage between populations, samples, the process of the selection of samples and how they were applied in this study is provided below.

3.4.1 The research population and sample

The research population is a group of elements, cases or individuals, objects, or organisations that conform to specific criteria and to which the researcher intends to generalize the result of the study (McMillan & Schumacher, 2010:129) as far as is possible. In other words, the population is the totality of individuals who have certain characteristics and are of interest to a researcher. According to McMillan and Schumacher (2010:129) and Welman, Mitchell and Kruger (2005:52), since the population is a larger representative of the participants for a study or too scattered geographically to study directly, it is impossible and not cost effective to study all the participants and therefore, a smaller group of participants are selected for study by means of a particularly

chosen sampling technique. Thus, the sample selected is a representative of the total research population (De Vos et al., 2002:89). The most basic considerations in sampling are size and representativeness. The size must be adequate to allow estimates of the characteristics of phenomena with reasonable precision. Graziano and Raulin (2000:133 in De Vos et al., 2002:198) stress that it is important to understand the concept of representativeness and its relationship to generalisability. The findings of a study can only be generalized when it is assumed that what is observed in the sample of subjects would also be observed in any other group of subjects from the population.

The accessible population for this study were the primary schools in proximity to the researcher who resides in Ile-Ife Town, south-western Nigeria. Three schools are selected for study in this area. Each of the schools represents different socio-economic characteristics which was the criterion for study. These schools are under the supervision of Ile Ife central Local Government District. All the schools have qualified teachers who are adequately paid. In addition, the schools use English as the language of teaching and learning, and as the language of communication. The schools were named for the purpose of the study: School A –representing a HSES community, School B representing a MSES community and school C representing a LSES community. At school C, in addition to teaching in English, teaching is also offered in the local language, namely Yoruba dialect.

Teachers who teach at the three selected primary schools and parents or guardians of the pupils that are attending the schools further comprised the research population. At school A, the total numbers of teachers are 14, at School B there are 45 teachers while at school C there are 28 teachers. Therefore, the target population of the study consisted of all the teachers from selected schools. At each of the schools, the researcher purposely selected five teachers from the school principals’ staff list. These five teachers represented the teacher sample. The guidance of the principal was sought regarding which of the teachers on the staff list would be most able to give adequate information about the topic under investigation and who had substantial teaching experience. The sampling technique used was thus purposive convenience sampling.

At School A 125 pupils are enrolled; at school B, 850 pupils are enrolled; at School C the pupil population comprised 450 pupils on the enrolment list. At each of the schools the researcher sampled five parents who volunteered to participate in the study. Parents were informed of the

study through a letter which the teacher distributed (see Appendix 4). The letters were personally handed to the parents by the teacher when they picked up their children from school. In the letter the research purpose and process were explained. Parents were informed that the research aimed to establish the nature and scope of PI in the particular school and that parent volunteers were sought to be interviewed with regard to their involvement in their children’s schooling. They were thus invited to be involved in the study voluntarily. It was through parents volunteering their participation that the parent sample was put together. The parents who elected to participate in the study returned the informed consent slip to the researcher. The informed consent slip was included at the bottom of the letter explaining the study which had been distributed to the parents by the teacher. The first five parents from each school who volunteered participation were selected. When too many parents volunteered their participation, the researcher explained to these individuals that the required number of participants had been found and thanked them for their willingness to be part of the study. It was made clear to them that they would be called upon to participate in the study if more information on the topic was sought.

3.4.2 Sampling technique

Sampling methods are generally categorised as probability or non-probability sampling. Probability sampling is a method of sampling that uses some form of random selection. Non- probability sampling methods are categorized as either accidental or purposive. With accidental or convenience sampling, the units are chosen just because they happened to be there at the time. With purposive sampling the process is approached with a specific plan and group of respondents in mind (Trochim, 2006).

In this research purposive convenience sampling and volunteer sampling techniques were utilized. Purposive sampling entails reliance on certain judgement by the researcher to select a sample that is a representative of the population or that includes subjects with needed characteristics. Convenience sampling implies using a group of respondents on the basis of their being accessible (McMillan & Schumacher, 2010:137). Volunteer sampling, which is a form of non-probability sampling, occurs when research respondents self-select to become part of the study. Most likely these individuals have a strong interest in the topic of the research and want to be involved in having their voices heard (Judd, 2006: 322).

As outlined in 3.4.2 the schools were selected on the basis of convenience since they are located close to where the researcher lives and were easily accessible to the researcher. Furthermore, since one of the criteria of the research was to involve schools representing different socio-economic environments, the three schools were purposively selected on the basis of this requirement. Each of the three schools in the area represented a different SES as required by the purpose of the study. Convenience sampling was thus considered to be the best approach to use in this particular study to select participating schools because the primary purpose of the research was not necessarily to generalize but to gain a better understanding of the relationship that exists between the nature and scope of PI within different SES schools and how parents and teachers perceive this relationship (McMillan & Schumacher, 2010: 137).

Teachers who participated in this study were staff in the three selected schools. Since the teachers were selected on the basis of their ability to best provide key information to address the purpose of the research as judged by the school principal, and also based on the extent of their teaching experience, purposive sampling was used to select teacher research participants.

The parents who participated in the study were selected by volunteer sampling. This sampling technique entails a request from the researcher for the participants to take part in the study. According to McMillan and Schumacher (2010: 145), volunteering sampling tends to be less conforming, less authoritarian and a more sociable approach. Parents were informed of the study through an information letter with an attached consent slip and were asked to volunteer their participation. As explained previously, the first five parents from each school who volunteered were selected. No other sampling criterion was used in selecting parents.