Qualitative research involves the systematic investigation of a phenomenon in a narrative and a descriptive way. Qualitative research appears to be more realistic in some of the concepts that cannot be expressed in mathematical analysis. However, it lacks uniformity and reliability because respondents have an option to ignore some concepts and chose others during data collection. The sampling method in qualitative research involves taking information from a given section of a community or a study population that has been selected for particular research. Ideally, the research objective and the uniqueness of the particular population are major determinant factors that influence the selection of a sample to be used in the research.
Generally, three major sampling techniques are often used in qualitative research, namely, “purposive sampling, quota sampling, and snow-ball sampling.” Generally, qualitative research only uses a small sample size in the research process since it does not largely base its findings on the sample size compared to quantitative research, which mostly relies on large samples, which is essential in this case because of its research design. The implication is that the data obtained is less reliable in qualitative research than that of quantitative research.
The validity of qualitative research is an important aspect of any scientific research; it involves measuring the extent to which the data is credible. In this qualitative research, the validity of any data can be described in terms of how much the data is credible, transferable, or how much the data can be verifiable. In this type of research, the information generated may be impossible to validate since a large aspect of it is dependent on the experience of the researcher due to the subjective interpretation of the data that is involved. However, qualitative data can be valid if the data is anything that can be dependable by other researchers and verified as far as its findings are concerned, but this is not easy in qualitative research.
Another difference is that qualitative research is not effective in analyzing causality between two or more variables compared to quantitative research; as a result, qualitative research is considered not highly valid and reliable because the research tends to incorporate their subjective interpretations such as opinion, feelings in both data collection and analysis which unfortunately tends to change among researchers. This is clear when more than one individual undertakes the same research using qualitative procedures under the same conditions. It is more likely there will be variation in the outcome in some aspects due to individual preferences, experiences, and socialization in life.
On the other hand, quantitative research involves systematic practical, scientifically developed methodologies to undertake research inquiries of quantitative properties aimed at developing mathematical derivations of observable facts and their relationships. Thus, from this definition, it is generally clear that quantitative research is mostly applicable in collecting data that mainly involve the use of statistics.
Normally validity of any quantitative research is an important concept, especially if the sample of a data collected is large enough; for this reason, quantitative research involves specifying “dependent and independent variable,” which can be used to test the credibility of research findings. In this regard, the degree of validity of data in quantitative research is much higher than qualitative since it uses numbers in standard form. This large sample is mostly randomly selected and involves data collection and analysis that is very objective.
Therefore, a quantitative approach is a reliable and objective method; in fact, the design of this research involves a lot of checks and balances that are intended to prevent issues of bias in data collection and interpretation. Moreover, quantitative research can be more reliable because the research process is undertaken in a systematic manner that would allow different researchers with varied experiences and social backgrounds to arrive at the same results; this is described as the uniformity of the study.