Robustness of the F-Test to Errors of Both Kinds and the Correlation Between the Numerator and Denominator of the F-Ratio

Donaldson, Theodore S.

doi:10.2307/2284037

Cited by 86 publications

(74 citation statements)

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“…Given the robust nature of the repeated measures ANOVA to violations of normality under the central limit theorem (Donaldson, 1968; Norman, 2010), we performed a repeated measures ANOVA with time (T1–T5) as within-subject variables and SCL-90 as the dependent variable. We also performed a non-parametric test (Friedman) to see whether its results confirmed the outcome of the repeated measures ANOVA.…”

Section: Resultsmentioning

confidence: 99%

A trauma-focused approach for patients with tinnitus: the effectiveness of eye movement desensitization and reprocessing – a multicentre pilot trial

Rikkert

Rood

Roos

et al. 2018

European Journal of Psychotraumatology

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Background: While normal tinnitus is a short-term sensation of limited duration, in 10–15% of the general population it develops into a chronic condition. For 3–6% it seriously interferes with many aspects of life. Objective: The aim of this trial was to assess effectiveness of a trauma-focused approach, eye movement desensitization and reprocessing (EMDR), in reducing tinnitus distress. Methods: The sample consisted of 35 adults with high levels of chronic tinnitus distress from five general hospitals in the Netherlands. Participants served as their own controls. After pre-assessment (T1), participants waited for a period of 3 months, after which they were assessed again (T2) before they received six 90 min manualized EMDR treatment sessions in which tinnitus-related traumatic or stressful events were the focus of treatment. Standardized self-report measures, the Tinnitus Functional Index (TFI), Mini-Tinnitus Questionnaire (Mini-TQ), Symptom Checklist-90 (SCL-90) and the Self-Rating Inventory List for Post-traumatic Stress Disorder (SRIP), were completed again halfway through treatment (T3), post-treatment (T4) and at 3 months’ follow-up (T5). Results: Repeated measures analysis of variance revealed significant improvement after EMDR treatment on the primary outcome, TFI. Compared to the waiting-list condition, scores significantly decreased in EMDR treatment [t(34) = −4.25, p < .001, Cohen’s dz = .72]. Secondary outcomes, Mini-TQ and SCL-90, also decreased significantly. The treatment effects remained stable at 3 months’ follow-up. No adverse events or side effects were noted in this trial. Conclusions: This is the first study to suggest that EMDR is effective in reducing tinnitus distress. Randomized controlled trials are warranted.

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Section: Resultsmentioning

confidence: 99%

A trauma-focused approach for patients with tinnitus: the effectiveness of eye movement desensitization and reprocessing – a multicentre pilot trial

Rikkert

Rood

Roos

et al. 2018

European Journal of Psychotraumatology

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“…In experimental research, in which the predictors in the linear model represent groups of people in different treatment conditions, the 'overall fit of the model' becomes a test of whether group means differ. Early work suggested that F controls the Type I error rate under conditions of skew when group sizes are equal (Donaldson, 1968;Glass, Peckham, & Sanders, 1972). However, more recent investigations revealed that differences in skewness, non-normality and heteroscedasticity interact in complicated ways that impact power (Wilcox, 2017).…”

Section: Misconceptions About Robustnessmentioning

confidence: 99%

Robust statistical methods: A primer for clinical psychology and experimental psychopathology researchers

Field

Wilcox

2017

Behaviour Research and Therapy

349

227

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This paper reviews and offers tutorials on robust statistical methods relevant to clinical and experimental psychopathology researchers. We review the assumptions of one of the most commonly applied models in this journal (the general linear model, GLM) and the effects of violating them. We then present evidence that psychological data are more likely than not to violate these assumptions. Next, we overview some methods for correcting for violations of model assumptions. The final part of the paper presents 8 tutorials of robust statistical methods using R that cover a range of variants of the GLM (t-tests, ANOVA, multiple regression, multilevel models, latent growth models). We conclude with recommendations that set the expectations for what methods researchers submitting to the journal should apply and what they should report. Keywords Robust statistical methods, assumptions, bias ROBUST ESTIMATION 3 Robust statistical methods: a primer for clinical psychology and experimental psychopathology researchers OverviewThe general linear model (GLM), which is routinely used in clinical and experimental psychopathology research, was once thought to be robust to violations of its assumptions. However, based on hundreds of journal articles published during the last fifty years, it is well established that this view is incorrect. Moreover, modern methods for dealing with the violations of these assumptions can result in substantial gains in power as well as a deeper, more accurate and more nuanced understanding of data. We begin with an overview of the key assumptions underlying the GLM. We then review various misconceptions about how robust the GLM is to violations of those assumptions and look at the effects that violations can have. We end the first section by looking at the evidence that psychological data, in general, are likely to violate the assumptions of the GLM.In part 2 of the paper we overview a selection of ways to deal with violations of assumptions that fall under the headings of data transformation, adjustments to standard errors, and robust estimation. In the final part, we present 8 tutorials that use datasets relevant to this journal to show how to implement a selection of techniques (robust estimators for model parameters and standard errors) for designs common to this journal (comparing dependent and independent means, predicting continuous outcomes from continuous predictors and longitudinal designs). ROBUST ESTIMATION 4The assumptions of the general linear model Critical assumptionsPsychology researchers (generally) and those with interests in psychopathology (specifically) typically apply variants of the general linear model to their data. In this model, an outcome variable (Y) is predicted from a linear and additive combination of one or more predictor variables (X). For each predictor there is a parameter that is estimated from the data (!) that represents the relationship between the predictor and outcome variable if the effects of other predictors in the model are held constant. There ...

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“…To estimate the influence that inequality of model means and the observational mean have on the validity of 176 using equation 3, we use equation 2.1 from Donaldson (1968), with the observational database taken as the "parent" …”

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confidence: 99%

Constraints on global oceanic emissions of N<sub>2</sub>O from observations and models

Buitenhuis¹,

Suntharalingam²,

Quéré³

2017

Preprint

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Abstract. We estimate the global ocean N2O flux to the atmosphere and its confidence interval using a statistical 9 method based on model perturbation simulations and their fit to a database of ΔpN2O (n=6136). We evaluate two 10 submodels of N2O production. The first submodel splits N2O production into oxic and hypoxic pathways following 11 previous publications. The second submodel explicitly represents the redox transformations of N that lead to N2O 12 production (nitrification and hypoxic denitrification) and N2O consumption (suboxic denitrification), and is 13 presented here for the first time. We perturb both submodels by modifying the key parameters of the N2O cycling

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Robustness of the F-Test to Errors of Both Kinds and the Correlation Between the Numerator and Denominator of the F-Ratio

Cited by 86 publications

References 8 publications

A trauma-focused approach for patients with tinnitus: the effectiveness of eye movement desensitization and reprocessing – a multicentre pilot trial

A trauma-focused approach for patients with tinnitus: the effectiveness of eye movement desensitization and reprocessing – a multicentre pilot trial

Robust statistical methods: A primer for clinical psychology and experimental psychopathology researchers

Constraints on global oceanic emissions of N<sub>2</sub>O from observations and models

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Robustness of the F-Test to Errors of Both Kinds and the Correlation Between the Numerator and Denominator of the F-Ratio

Cited by 86 publications

References 8 publications

A trauma-focused approach for patients with tinnitus: the effectiveness of eye movement desensitization and reprocessing – a multicentre pilot trial

A trauma-focused approach for patients with tinnitus: the effectiveness of eye movement desensitization and reprocessing – a multicentre pilot trial

Robust statistical methods: A primer for clinical psychology and experimental psychopathology researchers

Constraints on global oceanic emissions of N&lt;sub&gt;2&lt;/sub&gt;O from observations and models

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Constraints on global oceanic emissions of N<sub>2</sub>O from observations and models