5,257 research outputs found
Contro la funzionalizzazione della contrattazione collettiva. Riflessioni sul pensiero di Mario Rusciano
No full textL'autore riflette sul pensiero di Mario Rusciano in punto di funzionalizzazione della contrattazione collettiva.The author reflects on the thought of Mario Rusciano in relation to the subject of the functionalisation of collective bargaining
A comparison of methods for the analysis of binomial clustered outcomes in behavioral research
No full textBACKGROUND: In behavioral research, data consisting of a per-subject proportion of "successes" and "failures" over a finite number of trials often arise. This clustered binary data are usually non-normally distributed, which can distort inference if the usual general linear model is applied and sample size is small. A number of more advanced methods is available, but they are often technically challenging and a comparative assessment of their performances in behavioral setups has not been performed.
METHOD: We studied the performances of some methods applicable to the analysis of proportions; namely linear regression, Poisson regression, beta-binomial regression and Generalized Linear Mixed Models (GLMMs). We report on a simulation study evaluating power and Type I error rate of these models in hypothetical scenarios met by behavioral researchers; plus, we describe results from the application of these methods on data from real experiments.
RESULTS: Our results show that, while GLMMs are powerful instruments for the analysis of clustered binary outcomes, beta-binomial regression can outperform them in a range of scenarios. Linear regression gave results consistent with the nominal level of significance, but was overall less powerful. Poisson regression, instead, mostly led to anticonservative inference.
COMPARISON WITH EXISTING METHODS: GLMMs and beta-binomial regression are generally more powerful than linear regression; yet linear regression is robust to model misspecification in some conditions, whereas Poisson regression suffers heavily from violations of the assumptions when used to model proportion data.
CONCLUSIONS: We conclude providing directions to behavioral scientists dealing with clustered binary data and small sample size
Different methods to analyze clinical experiments with multiple endpoints: a comparison on real data
No full textMicroembolic signals and carotid plaque morphology: a study of 71 patients with moderate or high grade carotid stenosis
No full textConfronto delle tecniche di SPSS ed R per il calcolo dei gradi di libertà dei test per gli effetti fissi nei modelli lineari misti
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Valutazione tramite simulazioni della significatività del test Wilcoxon-Mann-Whitney, quando è violata l'assunzione di distribuzioni di forma identica nei campioni confrontati
No full textPrevalence-Value-Accuracy plots vs. ROC analysis to assess the diagnostic value of different ultrasound colour mappings of the carotid plaque, for a cerebrovascular condition
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