Predetermined sample size may guide sample size selection in quantitative research. On the contrary, during data collection in the qualitative study, the research waits until a point of saturation. Randomization is commonly used in quantitative research to reduce bias, whereas, in qualitative research, there are no such attempts during sampling. In qualitative sampling, a purposefully information-rich sample is selected from the overall population who provide information for the research. Such sampling techniques is considered a bias in quantitative research. Sampling techniques for quantitative research mainly draw upon probability principles. However, quantitative studies use non-probability sampling methods and designs.
Although differences exist between quantitative and qualitative research methods, both are similar in the sense that they both employ the concept of sampling. In both methods, research is carried out on a sample selected from the overall population. In most cases, the sample is a representation of the entire population. Both methods are used to conduct research and give valid and reliable results that can be used to solve problems in society. Both methods emphasize the value of accuracy and precision during sampling to ensure that the data is valid and reliable. Some scholars suggest the possibility of combining both qualitative and quantitative research techniques (Sandelowski, 2000).