Tests for Normality and Measures of Skewness and Kurtosis: Their Place in Research Reporting

1990 ◽  
Vol 50 (4) ◽  
pp. 717-729 ◽  
Author(s):  
Kenneth D. Hopkins ◽  
Douglas L. Weeks
2014 ◽  
Vol 9 (3) ◽  
pp. 290-305 ◽  
Author(s):  
Ahmed F. Siddiqi

Purpose – The purpose of this paper is to discuss how numerous tests that are available in statistical literature to assess normality of a given set of observations perform in normal and near-normal situations. Not all these tests are suitable for all situations but each test has an exclusive area of application. Design/methodology/approach – These tests are assessed for their power at varying degrees of skewness, kurtosis and sample size on the basis of simulated experiments. Findings – It is observed that almost all these tests are indifferent for smaller values of skewness and kurtosis. Further, the power of accepting normality reduces with increasing sample size. Originality/value – The article gives guidelines to researchers to apply normality assessing tests in different situations.


1975 ◽  
Vol 4 (11) ◽  
pp. 1009-1019
Author(s):  
L. A. Klimko ◽  
C. E. Antle ◽  
A. Rademaker
Keyword(s):  

2016 ◽  
Vol 32 (4) ◽  
pp. 291-297 ◽  
Author(s):  
Dubi Lufi ◽  
Shachar Pan

Abstract. Several studies have shown that Continuous Performance Tests (CPT) can diagnose Attention Deficit Hyperactivity Disorder (ADHD) better than other tests. Research reporting comparisons of two or more CPT-type tests is scarce. The purpose of the study was to compare the Mathematics Continuous Performance Test (MATH-CPT) with another CPT-type test (CPT II) and a questionnaire (the Brown Scale). The comparison was carried out by looking at correlations among subscales and checking the precision of detecting ADHD. Ninety-five high school and college students participated in the study, 41 with ADHD were the research group and 54 were the control group. The participants performed the two tests and answered the questionnaire. The results showed that the MATH-CPT correctly identified 74.50% of the participants of both groups as compared to the 71.60% of the CPT II. Correlations between the two CPT-type tests were moderate; however, they were similar to correlations found in other studies comparing similar tools. The MATH-CPT, final attention formula, showed significant correlations with the Brown scales, while the CPT II, confidence index associated with ADHD assessment, showed nonsignificant correlations with the questionnaire. The study indicated that MATH-CPT can be used with a clinical population of ADHD and for research purposes.


2017 ◽  
Vol 6 (4) ◽  
pp. 47-69 ◽  
Author(s):  
Dongjing Kang ◽  
Chigozirim Utah Sodeke

This essay emphasizes the writing of dialogical research as a crucial step in the dialogical research process. Dialogical research accounts should not suppress the ongoing struggles that accompany a genuine desire to engage dialogically in research contexts. Thus, we advocate and model evocative retellings of these struggles. Questioning our own fieldwork based on the work of Martin Buber and Mikhail Bakhtin, we highlight principles of dialogue that also serve as guidelines for dialogical research reporting: unfinalizability, engaging paradoxes, and creative (critical) transformation.


Author(s):  
Hussein Ali Sahib ◽  
Bassim Irhiem Mohammed ◽  
Ban A. Abdul Majid

Despite the unmistakable beneficial effect of clopidogrel on platelet aggregation,still there are some patient poorly responds to clopidogrel that may lead to worse cardiovascular clinical events.One hundred and twenty seven patients with cardiovascular disease (ACS,stroke,or TIA) were enrolled as a study group. Patients were recruited at coronary care unit (CCU) of Al-Yarmouk Teaching Hospital. Paletlet assessment was done by using light transmission aggregometry. between the patients that enrolled in this study there are significant inter-individual variability both skewness and Kurtosis were negative (-0.450,-0.130) respectively. 24% of patient enrolled in this study were hyporesponder.


Cancers ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 2421
Author(s):  
Roberta Fusco ◽  
Vincenza Granata ◽  
Mauro Mattace Raso ◽  
Paolo Vallone ◽  
Alessandro Pasquale De Rosa ◽  
...  

Purpose. To combine blood oxygenation level dependent magnetic resonance imaging (BOLD-MRI), dynamic contrast enhanced MRI (DCE-MRI), and diffusion weighted MRI (DW-MRI) in differentiation of benign and malignant breast lesions. Methods. Thirty-seven breast lesions (11 benign and 21 malignant lesions) pathologically proven were included in this retrospective preliminary study. Pharmaco-kinetic parameters including Ktrans, kep, ve, and vp were extracted by DCE-MRI; BOLD parameters were estimated by basal signal S0 and the relaxation rate R2*; and diffusion and perfusion parameters were derived by DW-MRI (pseudo-diffusion coefficient (Dp), perfusion fraction (fp), and tissue diffusivity (Dt)). The correlation coefficient, Wilcoxon-Mann-Whitney U-test, and receiver operating characteristic (ROC) analysis were calculated and area under the ROC curve (AUC) was obtained. Moreover, pattern recognition approaches (linear discrimination analysis and decision tree) with balancing technique and leave one out cross validation approach were considered. Results. R2* and D had a significant negative correlation (−0.57). The mean value, standard deviation, Skewness and Kurtosis values of R2* did not show a statistical significance between benign and malignant lesions (p > 0.05) confirmed by the ‘poor’ diagnostic value of ROC analysis. For DW-MRI derived parameters, the univariate analysis, standard deviation of D, Skewness and Kurtosis values of D* had a significant result to discriminate benign and malignant lesions and the best result at the univariate analysis in the discrimination of benign and malignant lesions was obtained by the Skewness of D* with an AUC of 82.9% (p-value = 0.02). Significant results for the mean value of Ktrans, mean value, standard deviation value and Skewness of kep, mean value, Skewness and Kurtosis of ve were obtained and the best AUC among DCE-MRI extracted parameters was reached by the mean value of kep and was equal to 80.0%. The best diagnostic performance in the discrimination of benign and malignant lesions was obtained at the multivariate analysis considering the DCE-MRI parameters alone with an AUC = 0.91 when the balancing technique was considered. Conclusions. Our results suggest that the combined use of DCE-MRI, DW-MRI and/or BOLD-MRI does not provide a dramatic improvement compared to the use of DCE-MRI features alone, in the classification of breast lesions. However, an interesting result was the negative correlation between R2* and D.


2021 ◽  
Vol 7 ◽  
pp. 237796082110242
Author(s):  
Anna E. Schierberl Scherr ◽  
Brian J. Ayotte ◽  
Marni B. Kellogg

Introduction Staff and equipment shortages and an easily transmissible virus make working in the COVID-19 pandemic demanding physically and psychologically. Nurses on the frontlines are particularly vulnerable to the adversity of working under these conditions, particularly with regard to mental health. Thus, understanding risk and protective factors for this vulnerable and essential group is critical for identifying potential targets of interventions. We had two aims for the current study: (a) to examine work functioning and symptoms of depression, anxiety, and posttraumatic stress (PTSD) among nurses who did and did not care for patients with COVID-19; and (b) to determine if resilience and social support moderate these relationships. Methods For three weeks in July 2020, nurses across the United States were invited to participate in an online survey collecting data on demographics, resilience, social support, and screening measures of depression, PTSD, anxiety, and distracted practice. Data were analyzed using descriptive statistics and hierarchical regression for each outcome measure. Conclusions Our findings support a growing body of research reporting that nurses are experiencing mental health sequelae during the COVID-19 pandemic, especially those providing direct care to patients with the virus. We found that compared to nurses who did not care for patients with COVID-19, those who did reported increased symptoms of PTSD, depression, and anxiety. A novel contribution is our finding that nurses providing direct COVID-19 care also experienced increased levels of distracted practice, a behavioral measure of distraction linking to a potential impact on patient care. We also found that resilience and social support acted as moderators of some of these relationships. Fostering resilience and social support may help buffer the effects of providing care to patients with COVID-19 and could potentially decrease nurse vulnerability to developing psychological symptoms and impairment on the job.


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