Abstract
Dyscalculia is a specific neurological affliction that disrupts a person's ability to understand and manipulate numbers. We intend to develop a serious game for children who attend primary school (up to 4th grade) and whose purpose is making the learning of basic mathematics (simple arithmetic) easier, by introducing specific mathematical problems and educational games that stimulate memory, among other aspects. To that end, we undertook a straightforward and preliminary evaluation of the serious game developed and present its results. Indeed, we believe that the findings of our pilot case study can be useful to determine some perceptions that may be vital to understanding the problems with teaching mathematics and the issues students face in this regard.

Abstract
This research aims at investigating which web accessibility and usability tools, with the focus on the ones that warrant automation, are available to assess the quality of interfaces for people with disabilities and/or special needs, enabling them to navigate and interact with web and mobile apps. Our search strategy identified 72 scientific articles of the most rated conferences and scientific journals, from which 16 were considered for the systematic literature review (SLR). We found that, despite the existence of various tools either for web or mobile apps, they are not completely effective, covering less than 40% of all the problems encountered. Also, no tool was found capable of adapting the application interfaces according to the type of disabilities that users may present. Therefore, a new tool could be a welcome advancement to provide full accessible and usable experiences.

Abstract
The use of mobile conversations is increasing all around the world. A conversational agent (CA) is mostly useful due to the fast response times and their simple nature. Recently, we have seen the development and increasing use of dialog systems on the Web. A conversational agent (CA) is a system capable of conversing with a user in natural language, in a way that it simulates a human dialog. Examples of CA can be found in several areas, including healthcare, entertainment, business, and education. In this paper a state of the art review of these dialog systems is presented, comprising different categories, different approaches and trends. The purpose of this work is to identify and compare the main existing approaches for building CA, categorizing them and highlighting the main strengths and weaknesses. Furthermore, it seeks to contextualize their use in an educational context and to discover the issues related to this task that may help in the choice of future investigations in the area of conversational natural language processing in educational context.

Abstract
Second Life (SL), a widely used Three-Dimensional Virtual World (3DVW), is being used as a tool for eLearning because of its interaction capabilities. On the other hand, accessibility is growing as a requirement for eLearning software tools, mainly because it can be an important factor for the learning process success by the impaired. In this paper we evaluate the accessibility of SL under WCAG 2.0/2.1 principles, and compare it with Moodle, which is a widely used web-based eLearning tool. We found that neither Moodle nor SL complies with accessibility under WCAG 2.0/2.1 rules, but SL does present itself as more accessible than Moodle. Moreover, WCAG 2.0/2.1 has several requirements specific for web pages, although they do not apply to 3DVWs. In this study, we intent to give a step forward towards evaluating emerging 3D virtual environments, like Metaverse, in the context of accessibility in the eLearning tools.

Abstract

Abstract
Nowadays statistics plays a major role either in society or in the research fields, with a particular emphasis in decision-making, therefore the importance of statistical inference. Statistical inference teaching is a new chapter, so this is an innovative study in Angola, since the scientific council of Polytechnic School of Malanje (PSM, Angola) had to agree to change the course syllabus in order to include the topics of statistical inference, in which confidence intervals (CI) and hypothesis testing were proposed by the first time in Angolan higher education. This work is part of a broader research that has adopted the theoretical framework of the Ontosemiotic Approach (OSA) since we are trying to overcome the error and difficulties of the students, using the semiotic conflict concept. Those conflicts are of two kinds: conflicts in using the new concepts of CI and conflicts that arise by the use of the spreadsheet. In this smaller work, we focus on the teaching of confidence intervals using the spreadsheet, in the course of Probabilities and Statistics in the PSM (Angola) during the academic year 2017/2018. The statistical inference through teaching confidence intervals in the course of Probability and Statistics of PSM was taught for the first time, as well as the a technologic tool, the spreadsheet. In this paper, our main goal is to present the classes planning of this module and it is qualitative and descriptive work. After the planning stage, we describe what the students were asked to do with the spreadsheet after completing the suggested problems using paper and pencil. The spreadsheet was selected since all students have it in their laptop and they may easily use it. During this first implementation of the CI classes, students did find the difficulties and made some of the errors described in the literature. Nevertheless, we noticed a great satisfaction from the students and they were motivated with this theme, and were very enthusiastic by the use of the spreadsheet and hopefully other topics in this Probabilities and Statistics course will also use it.