Peer 1 Parametric and non-parametric tests are used in the

Peer 1

Parametric and non-parametric tests are used in the statistical analysis of data from research studies. The selection of parametric versus non-parametric tests is based on whether or not data fits into pre-determined parameters. Parametric statistics are always correlated with a certain set of expectations that the data must meet because formulas of parametric statistics yield valid results only when the properties of the data are within the confines of these assumptions. It is assumed that the research study data are normally distributed for all parametric tests. If the data does not fit into parametric assumptions, it can be more appropriately categorized into nonparametric alternatives because nonparametric statistical procedures can convert original data to rank-ordered data (Gray et al, 2016).

An example of parametric analyses used to test for significant differences between group means of two independent samples is the independent samples t-test. The independent samples t-test examines differences between two independent groups. The samples are independent if the study participants in one group are unrelated to or different from the participants in the second group. Use of the independent samples t-test involves the assumptions that sample means from the population are normally distributed, the dependent or outcome variable is measured at the interval/ratio level, the two samples have equal variance, and all observations within each sample are independent (Gray et al, 2016). The non-parametric alternative to the independent samples t-test is the Mann-Whitney U test. The Mann-Whitney U test should be used if the data do not meet the assumptions involving normality or equal variances for an independent samples t-test. Mann-Whitney U calculations translate the data to ranks while eliminating any inconsistency or normalcy problems associated with the original values (Gray et al, 2016).

References

Gray, J., Grove, S. & Sutherland, S. (2016). Burns and Grove’s The Practice of Nursing Research: Appraisal, Synthesis, and Generation of Evidence. (8th ed.). Elsevier – Health Sciences Division. ISBN: 9780323377584

Peer 2

There are numerous differences between non-parametric and parametric tests which manifest in the form of the applicability of each of the test and the assumption that underlie them. The major difference between the two tests, however, is that the parametric test is the hypothesis test which provides generalizations for making statements about the mean of the parent population (Murray, 2013). In the contrast, the non parametric test is a hypothesis test which is not based on underlying assumptions (Varabyova & Schreyögg, 2013). In other words, the non parametric test does not require population’s distribution to be denoted by specific parameters. Also in the parametric test, the information regarding the population is known while in a non-parametric test, such information is totally unavailable.

Next, the two tests differ in terms of the level of measurement that may be used for each test. For the parametric test, the level of measurement is either is internal or ratio (John et al. 2013).  For the non-parametric test, on the other hand, the level of measurement is either nominal or ordinal. The other difference between the two tests manifests in the form of the measure of central tendency. For the parametric test, the primary measure of central tendency is the mean (Hoskin, 2012). In contrast, the measure of central tendency for the non parametric test is the median. Lastly, the correlation applied for the parametric and the non-parametric tests differ whereby the Pearson test is used for the parametric test while the spearman one is used for the non-parametric test.

An example of when the non-parametric test could be used in research is when the available data is not normal. For example, a researcher can consider the distribution of the available data and determine where a parametric or a non parametric approach should be used. If the researcher finds out that the available data is approximately normal, then it would be advisable to use parametric statistical tests (Murray, 2013). If the data is normal, on the other hand, then the non parametric test would be used. The non-parametric tests should only be specifically used when (John et al. 2013):

Distinctly non-normal and cannot be transformed

From a sample that is too small for the central limit theorem to lead to normality of averages

From a distribution not covered by parametric methods

From an unknown distribution

Nominal or ordinal

A parametric approach, on the other hand, should be used if (Murray, 2013):

The assumptions for the population probability distribution hold true

The sample size is large enough for the central limit theorem to lead to normality of averages

The data is non-normal but can be transformed.

References

Murray, J. (2013). Likert data: what to use, parametric or non-parametric?. International Journal of Business and Social Science, 4(11).

Varabyova, Y., & Schreyögg, J. (2013). International comparisons of the technical efficiency of the hospital sector: panel data analysis of OECD countries using parametric and non-parametric approaches. Health policy, 112(1-2), 70-79.

Hoskin, T. (2012). Parametric and nonparametric: Demystifying the terms. In Mayo Clinic (pp. 1-5).

John, J. M. M., Van Lishout, F., Gusareva, E. S., & Van Steen, K. (2013). A robustness study of parametric and non-parametric tests in model-based multifactor dimensionality reduction for epistasis detection. BioData mining, 6(1), 9

Table of Contents

Calculate your order
Pages (275 words)
Standard price: \$0.00

Latest Reviews

Impressed with the sample above? Wait there is more

Related Questions

Read the article: Impaired Nurses: Reclaiming Careers  APA Format for the

Read the article: Impaired Nurses: Reclaiming Careers  APA Format for the article: Vernarec, E. (2001). Impaired nurses: Reclaiming careers. The Carter Center. file:///Users/rm/Downloads/Impaired_Nurses_Reclaiming_Careers-1.pdf Step

For following questions answer True or False: The      central theme of

For following questions answer True or False: The      central theme of Jesus’ preaching/teaching was the kingdom of God,      meaning the reign/rule of God. _______ Jesus

Human Resource Management is an important part of facility operations

Human Resource Management is an important part of facility operations  and job descriptions are an important part of finding, hiring, and  training the right employees.

What is the impact of contextual factors on advocacy and

What is the impact of contextual factors on advocacy and policy? Contextual factors can range from internal (the organization, the practice, the environment, the culture,

Select a single short Platonic dialogue for analysis

For this essay please select a single short Platonic dialogue for analysis. Of the short dialogues, choose from: Lysis, Crito, Ion, or Clitophon. Your goal

Using research and readings outside of this course (making sure

Using research and readings outside of this course (making sure you always use citations for discussion question posts), identify 6 risk factors that are

Customer Survey

Chapter 7 Customer Survey Direction: In this assignment you will design a short customer satisfaction survey to be given to the physicians in the hospital.

Minoan society

Description For this assignment, you will need to look at some of the Greek myths that dealt with the Minoan society, particularly those of Daedelus,

Assignment Details When you were attending AIU, you thought of yourself

Assignment Details When you were attending AIU, you thought of yourself being an undercover narcotics officer or working for a bank as a fraud investigator,

Writing Instructions: Write 2 paragraphs responding to one of the “suggestions

Writing Instructions: Write 2 paragraphs responding to one of the “suggestions list” topics and use supporting evidence to prove your idea(s) Use at least one

What considerations need to be addressed within your community that are different form Debbie’s community?

An Epidemic in the Community To prepare for this Discussion, visit the CDC Wonder site in this week’s resources. Investigate the incidence and prevalence of

How to Develop an Effective Algebra Learning Plan

Algebra is a critical subject in academics, featuring in almost every discipline that requires quantitative analysis. However, mastering Algebra can be a daunting task for

New questions