When doing educational research, issues of validity and reliability need to be considered. For example, Opie (2004) defines validity as the degree to which a method, test or research tool actually measures what it is supposes to measure and reliability is defined as the extent to which the research instruments could produce similar results in a constant setting and validity as the degree to which the research instruments measure what they are intended to measure (Scaife, 2004).
According to Golafshani (2003), in qualitative research validity and reliability are understood in terms of trustworthiness, rigour and quality. Scaife (2004) explains trustworthiness of a case study research in terms of credibility. According to Scaife, credibility in a case study research is achieved through thoroughness in explaining the data-gathering procedures and how data have been analysed; reporting all instances in the research process including negative aspects; acknowledging biases; supporting claims with evidence; separating the researcher‟s own data from that obtained from other people and distinguishing interpretation from description. To ensure validity and reliability, several stages in preparing for and conducting the observation and structured interview was considered such as preparing the observation guide and interview schedule, piloting, and selecting the case study respondents.
Internal and respondent validity
The internal validity of the research data capturing tools needs to be checked (Scaife, 2004) and this was done by the supervisor. I did not attempt to generalize my results to a wider population of teachers; since the scale of my study is small. I do not aim to ensure external validity. Respondent validity was ensured by returning the interview transcripts to the selected teachers so that these teachers can check whether their responses accurately represent what they intended to say. According to Griffiths (1998), respondent validity can be ensured by taking the data and its analysis back to the subjects so that they can add or subtract their understanding. In an attempt to improve reliability of the results, the data collected from three classes that were taught by three different teachers were used.
Piloting instruments
The lesson observation guide and the interview schedule were piloted before using them in collecting data. After piloting, the instruments were modified as they seemed to cover a small portion of the research. The “contextual factors” were included to be part of the observation guide, and some of the interview questions were changed (i.e. question 6-8).
Triangulation
According to Golafshani (2003) and Scaife (2004), use of multiple procedures to collect data helps to address validity through triangulation. In this study, data was collected through observation of lessons, audio-recording and interviews with teachers. Triangulation helps me see the same issues from different perspectives and the methods.
3.12 ETHICS
Ethics is a set of principles that people use to decide what is wrong and what is right. According to Sike (2004), research ethics deals with the application of moral principles to avoid harming and affecting other people‟s life in the process of doing research. This research was a qualitative research and tends to be more intrusive in personal lives than quantitative research. The ethics of doing the research was considered by honouring the three aspects of conducting the research in schools, as given by Setati (2005), which are: negotiating access, providing feedback and exploring the nature of teachers‟ involvement in the study. Ethical guidelines regarding issues such as informed consents; confidentiality; anonymity; and privacy were adhered to (McMillan & Schumacher, 2006) (refer to appendix A to C).
Application for approval of the research to be conducted was done with the University of Witwatersrand ethics committee and Gauteng Department of Education. The University of Witwatersrand ethics guidelines requires that participants be informed about the nature of the research, consent forms be signed by participants before data collection commences and permission from organisations where the participants work should be obtained. Research only commenced after I obtained approval from the designated ethics committee of the University of Witwatersrand (appendix L).
Access was negotiated by sending request letters to the Gauteng Department of Education and to the principal of the school that was involved in the research (appendix M). A meeting was held with the three life science educators to inform them about the research and to invite them to participate. Consent forms accompanied by a subject information form were given to the participating educators. This was done to allow participants to decline from participating or to agree to participate. All participants were informed that all the information gathered from this research will be used for the purposes of this research only and will be kept safe until it is destroyed after a period of three to five years. Feedback will be provided to the teachers after the findings have been compiled in order to allow them to challenge my interpretations and claims. Names of schools, teachers and learners participating in this research were kept confidential. Only fictitious names were used.
To adhere to research ethics for the University of Witwatersrand and Gauteng Department of Education, I applied for clearance to conduct the research from the Human Research Ethics Committee of the University of Witwatersrand for the University of Witwatersrand and Gauteng Department of Education. The University of Witwatersrand committee cleared me to conduct this study in a letter, Protocal: 2009ECE45 (appendix L) and the Gauteng Department of Education also allows me to conduct this research (appendix M).
Information collected during the study was treated confidentially. Interviews were conducted individually and in secured places to avoid interruptions as well as to keep information given confidential. Information obtained was kept confidentially by the researcher and used for the purpose of the research report only. Pseudonyms have been used where reference has been made to the teachers or their schools and no record of names of teachers and schools was kept.
3.13 CONCLUSION
The chapter has explained what was done and why it was done in the research process to assist the reader in understanding the choice of the research design. In the next chapter I presented the results and analysis of the data.