Juan José Montaño Moreno

Using the R-MAPE index as a resistant measure of forecast accuracy

BACKGROUND The mean absolute percentage error (MAPE) is probably the most widely used goodness-of-fit measure. However, it does not meet the validity criterion due to the fact that the distribution of the absolute percentage errors is usually skewed to the right, with the presence of outlier values. In these cases, MAPE overstates the corresponding population parameter. In this study, we propose an alternative index, called Resistant MAPE or R-MAPE based on the calculation of the Huber M-estimator, which allows overcoming the aforementioned limitation. METHOD The results derived from the application of Artificial Neural Network (ANN) and Autoregressive Integrated Moving Average (ARIMA) models are used to forecast a time series. RESULTS The arithmetic mean, MAPE, overstates the corresponding population parameter, unlike R-MAPE, on a set of error distributions with a statistically significant right skew, as well as outlier values. CONCLUSIONS Our results suggest that R-MAPE represents a suitable alternative measure of forecast accuracy, due to the fact that it provides a valid assessment of forecast accuracy compared to MAPE.

From Diagrams to Self-Regulated Learning: Student Teachers' Reflections on the Construction of Their PLE.

Abstract This paper presents a study on the reflections on their PLEs by student teachers in an ICT subject of the fourth degree course in Teacher Education (Early Childhood Teacher Training) at the University of the Balearic Islands (UIB). There were four student teacher groups (n = 117) participating in this project, from the three Balearic Islands’ campuses (Mallorca, Menorca and Ibiza). The main research issues focused on in this study are: the topics highlighted from the reflections on the students’ PLEs and the reflection level achieved. To explore these issues, a content analysis technique has been used to interpret their final assignment of the students’ eportfolios, in which they had to carry out their reflections on their PLEs. For that purpose, two instruments have been designed: a system of categories and a rubric of assessment. Results show that the topics on which students reflect most are the conception of the PLE, its explicitness and its purpose. Although some improvement in students’ reflective skills was observed, conclusions lead us to the necessity of working further on the depth of reflections in order to adequately support self-regulated learning.