J48Consolidated: an implementation of CTC algorithm for WEKA

The CTC algorithm, Consolidated Tree Construction algorithm, is a machine learning paradigm that was designed to solve a class imbalance problem, a fraud detection problem in the area of car insurance [1] where, besides, an explanation about the classification made was required. The algorithm is based on a decision tree construction algorithm, in this case the well-known C4.5, but it extracts knowledge from data using a set of samples instead of a single one as C4.5 does. In contrast to other methodologies based on several samples to build a classifier, such as bagging, the CTC builds a single tree and as a consequence, it obtains comprehensible classifiers. The main motivation of this implementation is to make public and available an implementation of the CTC algorithm. With this purpose we have implemented the algorithm within the well-known WEKA data mining environment http://www.cs.waikato.ac.nz/ml/weka/). WEKA is an open source project that contains a collection of machine learning algorithms written in Java for data mining tasks. J48 is the implementation of C4.5 algorithm within the WEKA package. We called J48Consolidated to the implementation of CTC algorithm based on the J48 Java class.

Project work in a Basque L2 classroom: students’ perceptions

[EN] Project Work has been acknowledged as an efficient medium for language learning for more than two decades (Stoller, 2006) according to the numerous successful applications of project-based programmes that have been reported. In spite of the lack of sufficient controlled studies to assess the benefits of project work, and the existence of some studies giving evidence of students discontent with project work, the reports given by second language (SL) and foreign language students (FL) who have experienced project based instruction give support to the success attributed to project-based learning, as they recognised having improved language skills, learnt content, developed real life skills, as well as gained in self-confidence and motivation (Sierra, 2008 and 2011; Stoller, 2006). The aim of the present study is to explore some key issues involved in implementing a project-based programme focusing on the students’ perceptions of learning gains, their views on the collaborative assessment scheme used in the programme, and the students’ overall evaluations of the implementation of project work in a post-compulsory secondary education context in Navarre, Spain, with students learning Basque as a second language. A group of 12 students enrolled in a project work based programme participated in the study. Results showed that the students’ perceptions were very positive concerning doing projects, learning gains and group work, although more grammar instruction and teacher-fronted activities were requested by the students. However, the collaborative assessment process and the use of a Notebook/Diary as a reflection tool bore mixed evaluations.