When looking at research in nursing an important aspect of a study is the quality and size of the sample used for the research method. There are two major types of research qualitative and quantitative. In qualitative research the focus is on the overall quality of the information rather than the actual number of participants (Ellis, 2020). The sample size of the study depends on the information that the researcher needs to obtain. For example, if a sample size is too small the study may lack the data may be insufficient and if the sample is too big the data may be over saturated. For qualitative research, researchers soften use convenience sampling, which is done to choose participants who fit the researcher’s criteria for the study (Ellis, 2020). This type of sampling is not random. The overall size of the sample is usually adequate when saturation is met, this is the redundancy of the data of the overall sample (Ellis, 2020).
In comparison to qualitative research, the ideal number of participants in a quantitative research study generally starts around 30-50 participants (Ellis, 2020). A larger sample size is often needed to the nature of the study in terms of variables, and using a control group. For most quantitative designed studies, the sample size can be determined by using a power analysis, which is around 80% (Gray et al., 2017). Overall, descriptive studies tend to have the smallest sample, other than experimental studies. On the other hand, cohort and cross sectional research studies tend to have larger samples (Ellis, 2020). Another important aspect of quantitative research to look at is number of variables involved in the study. As the number of variables in a study increase, so too does the sample size (Gray et al., 2020).
Sampling Size for my Topic/PICOT Question
Hypothetically for my topic, I would choose to do use a quantitative sample. My topic focuses around blood pressure management in African Americans using either lifestyle modifications or medications to decrease their blood pressure over the course of a year. Due to the nature of the type of the topic, I would use a comparative descriptive design study, which is a quantitative research methodology (Ellis, 2020). I would use a quantitative research design to focus on the two groups of participants, one with lifestyle modifications alone and the other taking medications alone. For my sample type, I would use a probability sample to ensure participants are placed into groups at random (Ellis, 2020). To determine the sample size, I would use a power analysis to obtain an 80% power level, this allows the researcher to know whether the results are true or not (Gray et al., 2017).