Nou web de la Biblioteca Virtual: test amb usuaris, desembre 2013

Informe de l'anàlisi realitzat sobre el nou web de la Biblioteca Virtual de la UOC, per tal d'avaluar el grau d'usabilitat de la nova eina. És el segon test amb usuaris que es realitza del nou web i s'han analitzat els següents aspectes: l'accés a la col·lecció digital, les cinc funcionalitats més utilitzades del web i les cinc funcionalitats menys visibles del web.

The coal bearing Cenozoic As Pontes Basin (NW Spain): Geological influence on its coal's characteristics

Lignite deposits in the Cenozoic As Pontes strike-slip basin (northwestern Spain)were formed as a function of specific paleoclimatic conditions and tectonic evolution of the basin.

Problems of the randomization test for AB designs

N = 1 designs imply repeated registrations of the behaviour of the same experimental unit and the measurements obtained are often few due to time limitations, while they are also likely to be sequentially dependent. The analytical techniques needed to enhance statistical and clinical decision making have to deal with these problems. Different procedures for analysing data from single-case AB designs are discussed, presenting their main features and revising the results reported by previous studies. Randomization tests represent one of the statistical methods that seemed to perform well in terms of controlling false alarm rates. In the experimental part of the study a new simulation approach is used to test the performance of randomization tests and the results suggest that the technique is not always robust against the violation of the independence assumption. Moreover, sensitivity proved to be generally unacceptably low for series lengths equal to 30 and 40. Considering the evidence available, there does not seem to be an optimal technique for single-case data analysis