O' Leary, (2004) defines methodology as a particular set of principles that provides theoretical explanation to a particular set of modular assumptions needed in conducting a research study. Payne and Payne, (2004) further added that methodology is used to indicate a set of conceptual and philosophical assumptions that justify the use of a particular method. It can also be defined as a system of methods and rules which are used to aid the collection and analysis of data (Hart, 1998). From the above definitions, it can be deduced that methodology provides the basis for critical analysis of the theories and assumptions on the particular topic being researched.
The theoretical perspective of this research is post positivism and the stances are as follows:
Ontology: This takes the view of the critical realist; stating that even though the reality is out there, it can never be fully explored since it is under the control of natural laws that can only be partially understood (Guba, 1990). From the research question, certain factors are responsible for polio being endemic in Nigeria while some are enhancing its eradication by immunization. Therefore, this research study seeks to fully explore these factors.
Epistemology: Objectivity remains a controlling model but this can only be estimated by attributing more importance to external factors such as decisive community and critical tradition (Guba, 1990). An objective stand is maintained throughout this research study and this stand helps to eliminate bias so as to ensure rigour and credibility.
The methodology for this research is a literature review. Literature review has been selected in order to explore the various factors enhancing or hindering the success of immunization towards eradicating polio from Nigeria in a broader perspective from previous studies. The literature review enables easy collection of data from a wide range of sources and the understanding of different views of authors on the topic thereby identifying gaps for further research.