Research studies need not only start with efficient study design to address the hypothesis of the study but also the determination of the appropriate number of participants that will be involved in the study. It is true that the sample size is dependent on the study design, on statistical analysis used to answer the study questions, and on the anticipated association between the outcome and the risk factor. The sample size should not be too large as it wastes money and time both to the investigators and participants in the study. It should not be too small as well because it may lead to inaccurate results causing a waste of time and resources. In addition, participates in a large sample size may be exposed to unnecessary risk. Therefore, careful attention should be taken while determining the appropriate sample size for any study as it raises the question of ethical practices.
Any researcher should define the main objective of the study or the research question and the study design before selecting a representative sample size. Then the proportion of participants, and the value of the numbers to put in the formula is considered before determining the sample size. Kamangar & Islami (2013) states that the non-statistical consideration in determining the sample size are the availability of the fund, ethical issues, number of participants available, the novelty of the study, and any similar studies being conducted etc. The investigators give the rationale why their study is
According to the National Statement on Ethical Conduct in Human Research 2007, the assessment of risk-benefit ratio and consent from the participants are two important concerns of conducting any human research. These two issues help the participants to make an informed decision so that they can understand and outweigh the significance and possibilities of harm independently (Emanuel, 2008). Being a researcher, I would follow the National Statement on Ethical Conduct In Human Research 2007, hence, I must assess the magnitude of possible harm (physical, psychological, social, economic or legal) for the participants and handling the risk by identifying resources and monitoring them, thus, reducing the risk of their occurrence. (National statement on ethical conduct in human research,
The overall sample size, seems to be adequate. However, the fact that sample size for the nursing population is different for the
The research ethics, especially with the human subjects, is a very complex topic, and the completion of the certification opened my eyes on many aspects of research process. I learned how important it is to fully understand the research purpose and the methodology especially when selecting participants. I learned which populations are considered vulnerable, how to balance risk and potential benefits of research, and the importance of obtaining an informed, voluntary consent. I learned how important it is for researchers to ensure subjects confidentiality and privacy. Hardicre (2014) said that the research would be impossible without volunteers, and that the researchers “must act as patient advocates to ensure that every stage of the research
The number of participants in this study in each condition was 20. This is a quarter of the number of participants in the Chen et al study, which had 80 participants in each condition. Byford (2014) states that it is difficult to take the results of a small sample size and apply the results to the general population, and therefore one must be prudent when applying these results to a project or advertisement.
3. Sample Population: Who exactly was used in the study? How many? (Be as specific as possible.)
However, there are several limitations to this study. One, the sample size is small, and there results may not generalize to other populations. Second, the study was conducted for only six
Based upon information provided this study was appropriate conducted as a purposeful sampling but, this study
The lesson and case studies presented for evaluation was a great learning exercise. A better understanding of how to interpret data was gained. Also, weighing the clinical significance versus the statistical significance to show relevance is invaluable. All research is not quality research and one must be equipped to recognize bias, threats to validity and proper population representation. Moreover, critiquing the credibility of a study is essential to the health care advances.
Many randomised controlled trials involve large sample sizes because many treatments have relatively small effects. The size of the expected effect of the intervention is the main determinant of the sample size necessary to conduct a successful randomized controlled trial. Obtaining statistically significant differences between two samples is easy if large differences are expected. However, the smaller the expected effect of the intervention, the larger the sample size needed to be able to conclude, with enough power, that the differences are unlikely to be due to chance
What is the sample size? The sample size for this study was 233 patients and 148 nurses.
To ensure the results of the research are ethical and valid a proper sample design is necessary. A sample design consists of methods, sample frame, and sample size.
According to Machado et al. the population size for this study was 300 elderly people, of the population a formula for studies with groups was adopted with a 10% increase for losses and refusals (2017). This resulted in a sample group of 145 elderly persons that completed the study (Machado et al., 2017). Polit & Beck explain that the larger a sample size in relation to the population size, the less likely it is for a sampling error to occur (2017). In this case, the sample size appears to be sufficient to represent the population elderly people with
Cooper and Schindler (2014) provide examples of important questions to ask when conducting a study. These are mostly related to the collection of data, who collected the data, what were their credentials, when was the data collected, how large was the sample, from where was the sample taken, and so on. These types of questions address the reliability
When looking for a sample for a research project one must be sure that it is going to provide us with the answers to the questions we are looking to answer and it represents the sample that was in mind (Yegidis et al., 2012, p. 210). In the sex trafficking study, the researchers had obtained their participants by selecting 179 survivors of young ladies who had performed the act of sex trafficking. The ladies were selected from a pool of women who had been adjudicated between 1990-2011 (Hargreaves-Cormany & Patterson, 2016, p. 34). After reading the who research study I do feel that the sample size was effective and it gave the results that the researchers were looking for. The authors did not offer any justification for the sample size that was selected.
The project aim at teenagers, therefore sample group is between 13 to 19. I will set the sample sizes in 50 participants since it is easy to identity and more precision. If a sample sizes increase, it is very hard to estimate and become not accurate. Also, I’m worry about the extremes data can’t make a balance out, so the project prefers small sample sizes. It can take less effort to gain and maintain people, it is easy to produce significant results and comfortable to find a group of people. I will obtain samples from friends or friends’ sister and brother.