Comparing Two Groups: t-Tests

Williams, Leslie Lea; Quave, Kylie

doi:10.1016/b978-0-12-812775-9.00007-4

Cited by 2 publications

(3 citation statements)

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“…Furthermore, a t-test is applied for comparing the means of two groups of data; it determines whether the means of the two groups are equal ( Helsel et al., 2020 ). ANOVA is analogous to a t-test between three or more data groups and is governed by the same assumptions as to the t-test ( Williams and Quave, 2019 ). When two groups of elements such as Fe and Mn have equal means, it may suggest that they have similar origin ( Nnorom et al., 2019 ).…”

Section: Review Results and Discussionmentioning

confidence: 99%

“…However, their corresponding non-parametric tests are available for use when non-normality is suspected/ascertained. For instance, Spearman correlation instead of Pearson correlation, Wilcoxon Rank test in place of two-sample t-test, or the Kruskal Wallis test instead of ANOVA should be used ( Williams and Quave, 2019 ). These nonparametric tests have been said to exhibit greater power than do parametric tests in the presence of skewness and outliers ( Helsel et al., 2020 ).…”

Section: Review Results and Discussionmentioning

confidence: 99%

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An appraisal of data collection, analysis, and reporting adopted for water quality assessment: A case of Nigeria water quality research

Ewuzie

Aku

Nwankpa

2021

Heliyon

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The appropriate acquisition and processing of water quality data are crucial for water resource management. As such, published articles on water quality monitoring and assessment are meant to convey essential and reliable information to water quality experts, decision-makers, researchers, students, and the public. The implication is that such information must emanate from data obtained and analysed in an up-to-date, scientifically sound manner. Thus, inappropriate data analysis and reporting techniques could yield misleading results and mar the endeavours of achieving error-free conclusions. This study utilises the findings on water quality assessment in Nigeria over the last 20 years to reveal the likely trends in water quality research regarding data collection, data analysis, and reporting for physicochemical, bacteriological parameters, and trace organics. A total of 123 Web of Science and quartile ranked (Q1-Q4) published articles involving water quality assessment in Nigeria were analysed. Results indicated shortcomings in various aspects of data analysis and reporting. Consequently, we use simulated heatmaps and graphs to illustrate preferred ways of analysing, reporting, and visualising some regularly used descriptive and inferential statistics of water quality variables. Finally, we highlight alternative approaches to the customarily applied water quality assessment methods in Nigeria and emphasise other areas of deficiency that need attention for improved water quality research.

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Section: Review Results and Discussionmentioning

confidence: 99%

Section: Review Results and Discussionmentioning

confidence: 99%

An appraisal of data collection, analysis, and reporting adopted for water quality assessment: A case of Nigeria water quality research

Ewuzie

Aku

Nwankpa

2021

Heliyon

View full text Add to dashboard Cite

show abstract

“…This assumes as null hypothesis that data come from a standard normal distribution, which was here rejected at a 5% of significance level. When data for patients maintaining SR and relapsing to AF came from normal distributions, a Student’s t -test was used to assess statistical separability between them [ 59 ]. Otherwise, a Wilcoxon rank sum test was used for that purpose [ 60 ].…”

Section: Materials and Methodsmentioning

confidence: 99%

Multi-scale Entropy Evaluates the Proarrhythmic Condition of Persistent Atrial Fibrillation Patients Predicting Early Failure of Electrical Cardioversion

Cirugeda-Roldán

Calero

Manuel

et al. 2020

Entropy

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Atrial fibrillation (AF) is nowadays the most common cardiac arrhythmia, being associated with an increase in cardiovascular mortality and morbidity. When AF lasts for more than seven days, it is classified as persistent AF and external interventions are required for its termination. A well-established alternative for that purpose is electrical cardioversion (ECV). While ECV is able to initially restore sinus rhythm (SR) in more than 90% of patients, rates of AF recurrence as high as 20–30% have been found after only a few weeks of follow-up. Hence, new methods for evaluating the proarrhythmic condition of a patient before the intervention can serve as efficient predictors about the high risk of early failure of ECV, thus facilitating optimal management of AF patients. Among the wide variety of predictors that have been proposed to date, those based on estimating organization of the fibrillatory (f-) waves from the surface electrocardiogram (ECG) have reported very promising results. However, the existing methods are based on traditional entropy measures, which only assess a single time scale and often are unable to fully characterize the dynamics generated by highly complex systems, such as the heart during AF. The present work then explores whether a multi-scale entropy (MSE) analysis of the f-waves may provide early prediction of AF recurrence after ECV. In addition to the common MSE, two improved versions have also been analyzed, composite MSE (CMSE) and refined MSE (RMSE). When analyzing 70 patients under ECV, of which 31 maintained SR and 39 relapsed to AF after a four week follow-up, the three methods provided similar performance. However, RMSE reported a slightly better discriminant ability of 86%, thus improving the other multi-scale-based outcomes by 3–9% and other previously proposed predictors of ECV by 15–30%. This outcome suggests that investigation of dynamics at large time scales yields novel insights about the underlying complex processes generating f-waves, which could provide individual proarrhythmic condition estimation, thus improving preoperative predictions of ECV early failure.

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Comparing Two Groups: t-Tests

Cited by 2 publications

References 9 publications

An appraisal of data collection, analysis, and reporting adopted for water quality assessment: A case of Nigeria water quality research

An appraisal of data collection, analysis, and reporting adopted for water quality assessment: A case of Nigeria water quality research

Multi-scale Entropy Evaluates the Proarrhythmic Condition of Persistent Atrial Fibrillation Patients Predicting Early Failure of Electrical Cardioversion

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