Sample Size - Research Paper Example

Nursing Research Article Jemmott, J. B., Loretta, S. J., & Fong, G. T. (1998). Abstinence and Safer-Sex HIV Risk-Reduction Interventions for African American Adolescents. JAMA, 1-18. Method of Sample Size In every research study, it is crucial to determine and select the sample size for accuracy of the results. Sample size is the number of chosen units from which research data was gathered. The sample was from three schools of middle level in Philadelphia, Pa region serving low income African American communities. The sampling method used to determine the sample size in this case was clustering. Clustering is used for survey in a large geographical area such as province or district. The first step in clustering is selecting the clusters, which in this case were the three schools serving low-income African Americans. The second step is the selection of participants within the clusters, that is, the participating students who volunteered for the intervention study (Chambers & Skinner, 2003). In determining the sample size, the research selected participants from fixed number of schools, but there was no restriction on the number of students per school. Furthermore, since there was no clear precision or specific characteristics for the sample, the selection method could be referred to unaided judgment. Issues Related to Sample Size Related to the Purpose Among the issues related to the sample size is that they were from sixth and seventh grade classes with a mean age of 11.8 years. The purpose of the study is to take the participants through a program that would reduce development of devastating health problems among these participants. Another issue related to sample size is that among the participants, 53.0% were female, and since they were individuals still under adult care, 26.8% lived with both of their parents. Similarly, the selection criteria were based on volunteer by the participants with permission from their parents or guardians, and this also determined the sample size that the researchers ended up with at the end of the day. Moreover, there money was provided in exchange of participation, and given that these were students from low income families, this could have motivated the decision to volunteer, and thus, the sample size. Finally, there is the issue of low-income communities, which made the basis for the research, and thus, relates with the purpose of research. Adequacy of the Description There is a good description of the purpose and all the issues related to this interventions research study. For instance, the intervention program is adequately described from the purpose, objectives, and all the requirements, as well as the participants. Level of measurements of the variables The level of measurement for the variables in this research was ordinary level of measurement, which ranges the variables from low to high. This is because the variables in this intervention study allowed ordering, that is, could be classified into several categories of ordering. This can take the form of category 1, category 2, category 3, and so on. However, in this kind of measurement there is inconsistency in the range or distance between the categories. Thus, the difference between these categories present no meaning. P-Value The P-Value for this research was 0.02 Alpha value The alpha value was 0.05 Article 2 Hill, N., et al. (2003). Hypertension Care and Control in Underserved Urban African American Men: Behavioral and Psychological Outcomes at 36 Months. AJH, 906-913. Method of Sample size The original testable sample size for the study, that is, the original sample size was 821. However, at the end of it the researchers ended up with a sample size of 309 individuals who qualified for participation in the research study. The sampling technique employed in this case was stratified sampling. In stratified sampling, the population consists of a number of distinct categories, in which the frames are organized into strata. For instance, in the case of this research, the testable number was first divided into those who kept identification appointment, met criteria for screening 1, and met criteria for screening visit 2, and finally the category that qualifies to participate in the study (Chambers & Skinner, 2003). This categorizing and elimination ensures that the researchers end up with more efficient statistical estimates. This is because the samples are selected based on the relevance to the given criterion rather than the availability of the samples. This approach is convenient when it comes to aggregating data across groups. Another method applicable in this research was purposeful sampling, which focus on a limited number of participants or respondents because of in-depth information that would provide a good insight into the issue under investigation. The guidelines for sample size selection in this case is that they meet a given criterion of interest in the research such as clinical visits, they show wide variation in the characteristics required, and have specific characteristics that make the best candidates for the research. Issues related to sample size related to the purpose The African American population of participants consisted of men between the ages of 21 and 54 years. In addition, the population comprised participants residing in Baltimore and 38% similar to those screened on the baseline variables such as age, gender, and race among others. All these related to the purpose of the study, and the determination of the sample size. Other factors that played a critical role and basis for the purpose of the study were educational levels, employment nature, whether part-time or full-time. And finally, the other parameters considered in the selection of the sample size were those who’s BP was stable, and those who were under hypertensive medication, which relates with the purpose, as well. Adequacy of the description The description found in this research is moderately adequate as all the variables and concepts are clearly defined. As a result, all the procedures and methods provided in the research are clear and adequately understandable. Level of measurements of the variables In this case, the level of measurement of the variables was of the ordinal nature. This type of level of measurement entails ordering of variables by classifying them into particular categories. The outstanding feature of this level of measurement is that distance between the variables is inconsistence, thus, cannot be used to determine the meaning. P-Value P- Value is 0.05 Alpha level Alpha value is 0.01 References Chambers, R. L., & Skinner, C. (2003). Analysis of Survey Data. Wiley. Hill, M. N. (2003). Hypertension Care and Control in Underserved Urban African American Men: Behavioral and Psychological Outcomes at 36 Months. AJH, 906-913. Jemmott, J. B., Loretta, S. J., & Fong, G. T. (1998). Abstinence and Safer-Sex HIV Risk-Reduction Interventions for African American Adolescents. JAMA, 1-18. Read More