There are various methods of sampling selection depending on the type of research process. Kothari (2004) listed the important sampling designs such as deliberate sampling, random sampling, systematic sampling, stratified sampling, quota sampling, cluster sampling, multi-stage sampling and sequential sampling. The logic of statistical sampling is an abstract which starts from an idea of research object and distribution, in which material is put together according to certain criteria such as demographic, social situation, etc. (Flick, 1998). An alternative method of sampling is the strategy of complete collection. The sampling is limited to various criteria such as a specific age, region, a limited period and a particular material.
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In this thesis, Chapter 4 will perceive and evaluate the customers’ behaviour and intention towards reusable packaging and Chapter 5 will identify the reusable packaging attributes from customers’ perspective. Several dimensions of these samples have been defined such as all samples have the same types of developers and likelihood, a group of students as well as non-students, employees and non-employees, and the samples do not focus on specific gender, age or country (for more details about customer sample see Chapters 4 and 5). The sample size in this part of the thesis was validated through statistical analysis. Snowball sampling and random sampling methods were used. The snowball sampling concept of ‘who-knows-who’ asks participants who else should be participating (Malhotra and Birks 2006). Snowball sampling was used to escalate the potential number of contacts. Random sampling gives the chance for every member of a population to participate in the study in order to distinguish between random sample and population of interest.
Moreover, the experienced professionals involved in the packaging design and environmental impact were chosen to be the sample population as they would be aware of the importance of developing packaging and its influence on the environment. Owing to their ability to compare and define to what extent reusable packaging attributes are important to produce reusable packaging in various ways and also to what extent the environmental impact of reusable packaging attributes would reduce the environmental dilemma about packaging issues, they were the most suitable participants in this research. The experts consulted in this thesis have the adequate education, skills and experiences from the field (for more information about the experts see Chapters 5 and 6). The sample size in this part of the thesis was three experts in Chapter 5 and nine experts in Chapter 6. This sample size was considered acceptable for this particular study as Saaty (2001) found that a small sampling size of less than 10 experts is acceptable and necessary because the professionals should share a consistent belief. The convenience sampling method was used in this part of the thesis. Convenience sampling focuses on the data that are selected by those who provide it such as information from experts. Convenience sampling is used in this thesis due to the researcher’s knowledge of the experts in the area of packaging design and environmental impact from their published papers. The reason behind implementing the test cases in the next chapters is to provide a unique opportunity that will enhance the validity of data collected.
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This section describes the process of the data collection used in the thesis. The choice of data collection comes from the inadequacy of the data to deal with real-life problems. There are different types of data collection: primary data collection, which involves collecting new data, and secondary data collection, which concentrates on the existing data from previous studies. Primary data collection is the only method that has been used in this thesis because there is no secondary data available from previous studies as it is a new area of research.
Such an approach can entail qualitative and quantitative methods to gain and examine the data. Each method is based on the information used to study a phenomenon. The qualitative research method can be construed as information such as words, sentences and narratives whereas the quantitative research method can be construed as information such as numbers and figures (Bryman and Bell, 2011). Blumberg et al. (2011) stated that there is no such predominance of qualitative and quantitative methods. Flick (1998) stated that the qualitative method cannot be independent of the research process but is embedded in it. Also, the quantitative research method can explore new phenomena. Quantitative and qualitative studies represent different research strategies in terms of the role of theory. Therefore, it is obvious that the research problem can be investigated qualitatively and quantitatively. Owing to the scarcity of the research conducted in this area, this research needs to use an approach involving the use of multiple methods to understand the research problem.
In this thesis through conducting an intensive literature review about the customers’ behaviour and attitude in Chapter 4, various type of factors were identified and the quantitative method was needed to collect and analyse the data. An SD method was utilised through customers’ experiences in reusing packaging within their lifetime. In Chapter 5, various packaging attributes were identified in the literature review, which needed a quantitative method to use experts’ opinion through utilising the normal average method. In Chapter 6, owing to the need to discover the relationship of a number of environmental factors to the reusable packaging attributes, the quantitative PCA method, which utilises experts’ judgments, was used. Full explanations and discussions for SD, normal average and PCA methods are explained in Chapters 4, 5 and 6 respectively. However, in Chapter 5, there is the need to use a qualitative method to explore the attributes that persuade consumers to reuse packaging. This is achievable through the codes and coding method, which is a common approach that defines
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meaning from participants’ words. The results of the qualitative method assist in the design of a reusable packaging attributes checklist. The collected data in the previous section must be further analysed prior to being used in the other stage of the research. In order to ensure that the gathered data are reliable and consistent, an additional test was carried out in each technical chapter in the thesis. Qudrat-Ullah and Seong test and validation of the structure and behaviour of the SD model were carried out on the data collected (for more detail about the validation processes see Chapters 4 and 5).
3.6 Summary
This chapter has explained the various research designs in an effort to lay down the basis for the research. It has presented the main philosophical perspective behind the research methodologies. Research techniques, research design, sampling section, data collection and data analysis have been explained in detail with relation to the type of research techniques, type of sampling and the process of data collection used. The next chapter will provide the first part of the framework to discover the relationship between customers’ behaviour and intentions, and reusable packaging practices in order to identify the main aspects that lead to increasing the number of reusable packaging practitioners.
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