Skip to content
Research Article Open access CC BY 4.0

Robustness of T-test Based on Skewness and Kurtosis

Steven T. Garren, Kate McGann Osborne

Journal of Advances in Mathematics and Computer Science · pp. 102–110 · Published 7 Apr 2021

10.9734/jamcs/2021/v36i230342

Abstract

Coverage probabilities of the two-sided one-sample t-test are simulated for some symmetric and right-skewed distributions. The symmetric distributions analyzed are Normal, Uniform, Laplace, and student-t with 5, 7, and 10 degrees of freedom. The right-skewed distributions analyzed are Exponential and Chi-square with 1, 2, and 3 degrees of freedom. Left-skewed distributions were not analyzed without loss of generality. The coverage probabilities for the symmetric distributions tend to achieve or just barely exceed the nominal values. The coverage probabilities for the skewed distributions tend to be too low, indicating high Type I error rates. Percentiles for the skewness and kurtosis statistics are simulated using Normal data. For sample sizes of 5, 10, 15 and 20 the skewness statistic does an excellent job of detecting non-Normal data, except for Uniform data. The kurtosis statistic also does an excellent job of detecting non-Normal data, including Uniform data. Examined herein are Type I error rates, but not power calculations. We nd that sample skewness is unhelpful when determining whether or not the t-test should be used, but low sample kurtosis is reason to avoid using the t-test.

Chi-square distribution exponential distribution kurtosis laplace distribution normal distribution skewness T-distribution T-test uniform distribution

Cited by 22

Estudio piloto: viabilidad de la formación en línea en bioneuroemoción para docentes

Carmen L. Rivera-Medina, David Corbera Batlló, A. Inda · Educación y Educadores · 2024

Robust Framework for the detection of Alzheimer’s Disease via analysis of Spontaneous Speech Signals

Adnan Elahi, Danilo Comminiello, S. Marceglia · 2024 Signal Processing: Algorithms, Architectures, Arrangements, and Applications (SPA) · 2024

Save life! Optimization of dynamics for pharmaceutical distribution performance

Benjamin Mwakyeja, H. Kimario · Management Matters · 2024

Drama Experience in Upgrading Marketing Learners’ Competence in Improving Customer Satisfaction

Shuang Hao, Nalini Arumugam, Wenlin Li · International Journal of Religion · 2024

Gender Differences in Students’ Engagement Ratings of Instructor Presence in Online Courses

Kizito Mukuni, Doris Kincade, Xu-Qing Wang · Quarterly review of distance education · 2022

Using Kurtosis for Selecting One-Sample T-Test or Wilcoxon Signed-Rank Test

S. Garren, G. Davenport · Current Journal of Applied Science and Technology · 2022

Patient Expectations of Assigned Treatments Impact Strength of Randomised Control Trials

R. Truzoli, P. Reed, L. Osborne · Frontiers in Medicine · 2021

Article metrics

Real usage data collected on this platform.

0

Page views

0

PDF downloads

0

Outbound clicks

22

Citations

Views by country

Approximate, from request IP at view time — not citizenship or institution. Countries with fewer than 5 views are grouped as "Other".

No views recorded yet.

Traffic sources

Referring site, by host.

No traffic recorded yet.

Views and downloads exclude known bots/crawlers. Citations combines this platform's own DOI-resolved index with each external source's own reported total — see Cited by above for individually listed citing works. Last refreshed 0 seconds ago.