This chapter discusses data collection methods and strategies in quantitative research and how researchers design their studies following quantitative approaches. The chapter consists of four sections. The first section discusses experimental and non-experimental designs for quantitative research and the steps that are taken to achieve a more effective inquiry and valid findings. The second and third sections of the chapter discuss the quantitative data collection methods and sampling procedures of quantitative projects, respectively. The chapter is then concluded by examining the significance of reliability and validity concepts in quantitative projects. The chapter has also provided relevant examples and critical thinking challenges for enhanced understanding.
TopIntroduction
As noted in the first and second-chapters, research methods vary according to the paradigm or the philosophical approach is taken. The methods for quantitative studies would naturally be different from those employed by qualitative researchers. As also noted in chapter two, research studies will tend to vary due to the research characteristics adopted such as epistemology, ontology, axiology, methodology and rhetoric. This chapter will help the reader to appreciate positivists’ methods and how to undertake quantitative research studies. By the end of this chapter, the readers should be able to explain popular quantitative designs and identify or describe quantitative sampling procedures. The reader will also be enabled to examine the nature and characteristics of quantitative data collection methods and to test the reliability and validity of quantitative research instruments.
Case Study
John did a study on the attitudes of undergraduate students towards statistics. He claimed that his study was purely quantitative. The project used open interviews and purposive sampling methods. The external examiners rejected the work of John, they argued that open interviews and purposive sampling methods are not related to quantitative projects. John became angry and abandoned his program. By the end of this chapter, you should be able to understand the methods appropriate for quantitative projects.
In the case study above John failed his thesis because he did not understand the differences between quantitative and qualitative methods. Readers of this book should be able to appreciate the differences between quantitative and qualitative research methods and should be able to undertake purely quantitative, qualitative, or mixed methods studies with some demonstrated knowledge and understanding. This chapter is divided into the following subheadings;
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Background
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Quantitative Research Designs
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Quantitative Data Collection Methods
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Quantitative Sampling Procedures
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Reliability & Validity in Quantitative Research
Background
Since the positivist paradigm, upon which the quantitative approach is located, has been dealt with in chapter one, this section will focus its background more on Quantitative research designs, especially the experimental.
Quantitative Research Designs
Research designs control the processes and the way researchers undertake their studies. A research design is defined as an overall approach for data collection. Research designs control the selection of sample sizes, data collection and analysis techniques. There are various kinds of research designs. Qualitative research has several designs, Creswell & Clark (2007) highlights five qualitative traditions. The five qualitative traditions are; biography, phenomenology, ethnography, grounded theory and case study. They are among the most popular designs for the qualitative paradigm. Mixed methods research has its designs, the most common being triangulation, explanatory and exploratory designs (Ndanu & Syombua, 2015).
This chapter is only concerned with quantitative designs. Quantitative research designs are divided into two categories: experimental and non-experimental designs. Experimental designs are further divided into true and quasi-experiments. Non-experiment designs are categorized into correlation, survey, ex post facto and descriptive designs. The knowledge of research designs will help researchers to select proper methods of data collection, sample size and data analysis techniques. Studying research designs will also help researchers to understand the processes of undertaking research. Therefore, researchers are encouraged to study research designs in detail before undertaking their studies.