An R Library for Compositional Data Analysis in Archaeometry

Compositional data naturally arises from the scientific analysis of the chemical composition of archaeological material such as ceramic and glass artefacts. Data of this type can be explored using a variety of techniques, from standard multivariate methods such as principal components analysis and cluster analysis, to methods based upon the use of log-ratios. The general aim is to identify groups of chemically similar artefacts that could potentially be used to answer questions of provenance. This paper will demonstrate work in progress on the development of a documented library of methods, implemented using the statistical package R, for the analysis of compositional data. R is an open source package that makes available very powerful statistical facilities at no cost. We aim to show how, with the aid of statistical software such as R, traditional exploratory multivariate analysis can easily be used alongside, or in combination with, specialist techniques of compositional data analysis. The library has been developed from a core of basic R functionality, together with purpose-written routines arising from our own research (for example that reported at CoDaWork'03). In addition, we have included other appropriate publicly available techniques and libraries that have been implemented in R by other authors. Available functions range from standard multivariate techniques through to various approaches to log-ratio analysis and zero replacement. We also discuss and demonstrate a small selection of relatively new techniques that have hitherto been little-used in archaeometric applications involving compositional data. The application of the library to the analysis of data arising in archaeometry will be demonstrated; results from different analyses will be compared; and the utility of the various methods discussed

The Challenges of didactics on scholar inclusion: specialized teachers perceptions

This study is a section of the GP-FOREESP - Formation of Human Resources and Learning in Special Education Group’s agenda. This Group is engaged in the development of researches with the intent to contribute on the process to universalize the access to school as well as on the improvement of education system that is currently available to the target population of Special Education. Nowadays, the inclusion process subject has been prioritized by that research group, as they consider that, along with other reasons, the efforts to establish an inclusive education system would be the unique alternative to solve the problem regarding the access to school, which is currently limited, and also to improve the quality on special education, since the level presented in the country is low. Guided by such premise, the present work is a supplementary project developed within the group extent to generate knowledge on school inclusion matter

E-library: portal de lectura en línia

Conferència emmarcada dins el IV Workshop BiblioUdG on es presenta el nou portal llibres electrònics de Documenta Universitària