Exploration of geological variability and possible processes through the use of compositional data analysis: an example using scottish metamorphosed

Developments in the statistical analysis of compositional data over the last two decades have made possible a much deeper exploration of the nature of variability, and the possible processes associated with compositional data sets from many disciplines. In this paper we concentrate on geochemical data sets. First we explain how hypotheses of compositional variability may be formulated within the natural sample space, the unit simplex, including useful hypotheses of subcompositional discrimination and specific perturbational change. Then we develop through standard methodology, such as generalised likelihood ratio tests, statistical tools to allow the systematic investigation of a complete lattice of such hypotheses. Some of these tests are simple adaptations of existing multivariate tests but others require special construction. We comment on the use of graphical methods in compositional data analysis and on the ordination of specimens. The recent development of the concept of compositional processes is then explained together with the necessary tools for a staying- in-the-simplex approach, namely compositional singular value decompositions. All these statistical techniques are illustrated for a substantial compositional data set, consisting of 209 major-oxide and rare-element compositions of metamorphosed limestones from the Northeast and Central Highlands of Scotland. Finally we point out a number of unresolved problems in the statistical analysis of compositional processes

La Mejora de la docencia universitaria a través de la trasferencia de buenas prácticas = Improving college teaching through the transfer of good practice

La comunicación presentada forma parte del proyecto excelencia titulado: “Conocimiento y competencia profesional del profesor universitario sobre enseñanza y el aprendizaje en entornos de tecnología avanzada de la información y la comunicación”; que pretendía apoyar , desde la investigación de campo, la mejora de la actividad académica universitaria y difundir a nivel operativo acciones de innovación educativa y del uso de la tecnología avanzada en los procesos de enseñanza-aprendizaje, que permitiesen construir y recopilar el conocimiento profesional docente en la universidad