15 citations · 37 across the 28 of their papers we have counts for
15 papers · 1 filter
The Fisher score on the closed simplex
Giovanni Pistone, Fabio Rapallo, Eva Riccomagno
We extend classical analytic tools for finite-state statistical models to allow zero probabilities. Using methods from algebraic statistics and information geometry, we develop a f…
Zero patterns in multi-way binary contingency tables with uniform margins
Roberto Fontana, Elisa Perrone, Fabio Rapallo
We study the problem of transforming a multi-way contingency table into an equivalent table with uniform margins and same dependence structure. This is an old question which relate…
Circuit bases for randomisation
Elena Pesce, Fabio Rapallo, Eva Riccomagno +1
After a rich history in medicine, randomisation control trials both simple and complex are in increasing use in other areas such as web-based AB testing and planning and design dec…
On the aberrations of mixed level Orthogonal Arrays with removed runs
Roberto Fontana, Fabio Rapallo
Given an Orthogonal Array we analyze the aberrations of the sub-fractions which are obtained by the deletion of some of its points. We provide formulae to compute the Generalized W…
Algebra and geometry of tensors for modeling rater agreement data
Cristiano Bocci, Fabio Rapallo
We study three different quasi-symmetry models and three different mixture models of tensors for modeling rater agreement data. For these models we give a geome…
Unions of Orthogonal Arrays and their aberrations via Hilbert bases
Roberto Fontana, Fabio Rapallo
We generate all the Orthogonal Arrays (OAs) of a given size n and strength t as the union of a collection of OAs which belong to an inclusion-minimal set of OAs. We derive a formul…
Exact tests to compare contingency tables under quasi-independence and quasi-symmetry
Cristiano Bocci, Fabio Rapallo
In this work we define log-linear models to compare several square contingency tables under the quasi-independence or the quasi-symmetry model, and the relevant Markov bases are th…
Aberration in qualitative multilevel designs
Roberto Fontana, Fabio Rapallo, Maria-Piera Rogantin
Generalized Word Length Pattern (GWLP) is an important and widely-used tool for comparing fractional factorial designs. We consider qualitative factors, and we code their levels us…
Toric ideals with linear components: an algebraic interpretation of clustering the cells of a contingency table
Enrico Carlini, Fabio Rapallo
In this paper we show that the agglomeration of rows or columns of a contingency table with a hierarchical clustering algorithm yields statistical models defined through toric idea…
A Characterization of Saturated Designs for Factorial Experiments
Roberto Fontana, Fabio Rapallo, Maria-Piera Rogantin
In this paper we study saturated fractions of factorial designs under the perspective of Algebraic Statistics. We define a criterion to check whether a fraction is saturated or not…
Saturated fractions of two-factor designs
Roberto Fontana, Fabio Rapallo, Maria Piera Rogantin
In this paper we study saturated fractions of a two-factor design under the simple effect model. In particular, we define a criterion to check whether a given fraction is saturated…
Outliers and patterns of outliers in contingency tables with Algebraic Statistics
Fabio Rapallo
In this paper we provide a definition of pattern of outliers in contingency tables within a model-based framework. In particular, we make use of log-linear models and exact goodnes…
Geometry of diagonal-effect models for contingency tables
Cristiano Bocci, Enrico Carlini, Fabio Rapallo
In this work we study several types of diagonal-effect models for two-way contingency tables in the framework of Algebraic Statistics. We use both toric models and mixture models t…
A class of statistical models to weaken independence in two-way contingency tables
Enrico Carlini, Fabio Rapallo
In this paper we study a new class of statistical models for contingency tables. We define this class of models through a subset of the binomial equations of the classical independ…
The Geometry of Statistical Models for Two-Way Contingency Tables with Fixed Odds Ratios
Enrico Carlini, Fabio Rapallo
We study the geometric structure of the statistical models for two-by-two contingency tables. One or two odds ratios are fixed and the corresponding models are shown to be a portio…