Many educational institutions have been using online judges in programming classes, amongst others, to provide faster feedback for students and to reduce the teacher's workload. There is some evidence that online judges also help in reducing dropout. Nevertheless, there is still a high level of dropout noticeable in introductory programming classes. In this sense, the objective of this work is to develop and validate a method for predicting student dropout using data from the first two weeks of study, to allow for early intervention. Instead of the classical questionnaire-based method, we opted for a non-subjective, data-driven approach. However, such approaches are known to suffer from a potential overload of factors, which may not all be relevant to the prediction task. As a result, we reached a very promising 80% of accuracy, and performed explicit extraction of the main factors leading to student dropout.

While Massive Open Online Course (MOOCs) platforms provide knowledge in a new and unique way, the very high number of dropouts is a significant drawback. Several features are considered to contribute towards learner attrition or lack of interest, which may lead to disengagement or total dropout. The jury is still out on which factors are the most appropriate predictors. However, the literature agrees that early prediction is vital to allow for a timely intervention. Whilst feature-rich predictors may have the best chance for high accuracy, they may be unwieldy. This study aims to predict learner dropout early-on, from the first week, by comparing several machinelearning approaches, including Random Forest, Adaptive Boost, XGBoost and GradientBoost Classifiers. The results show promising accuracies (82%-94%) using as little as 2 features. We show that the accuracies obtained outperform state of the art approaches, even when the latter deploy several features.

Objectives:To assess vaccination timeliness, risk factors associated with delays and the reasons for delayed vaccinations among children below the age of 3 years in Jeddah, Kingdom of Saudi Arabia.Methods:This is a cross-sectional study conducted in Jeddah, Saudi Arabia during the period of May 2016 to August 2017. Data were obtained from parents of children under the age of 3 years using a structured questionnaire comprised of questions about sociodemographics, physical well-being of the child and the reasons that are used to justify delayed vaccinations. Vaccinations were considered delayed if they occurred more than 30 days after the time designated on the primary vaccination schedule. Logistic regression was used to assess the risk factors for vaccination delays.Results:The study included 351 children. Delayed vaccinations were observed in 85/351 (24.2%) of the sample. Delays were noted to occur most frequently for Measles, Mumps, Rubella vaccine (MMR), second dose of meningococcal conjugate quadrivalent vaccine (MCV4), second dose of oral polio vaccine (OPV) and fourth dose of pneumococcal conjugate vaccine (PCV) in 19/125 (15.2%) of the sample. Traveling at the time of vaccination was the most common delay reason and was reported in 31/142 (21.3%) of the sample.Conclusion:Adherence to vaccination is fairly common in this part of the country. However, vaccination delays are still present and should be addressed to improve health care.

Programming online judges (POJs) are autograders that have been increasingly used in introductory programming courses (also known as CS1) since these systems provide instantaneous and accurate feedback for learners' codes solutions and reduce instructors' workload in evaluating the assignments. Nonetheless, learners typically struggle to find problems in POJs that are adequate for their programming skills. A potential reason is that POJs present problems with varied categories and difficulty levels, which may cause a cognitive overload, due to the large amount of information (and choice) presented to the student. Thus, students can often feel less capable, which may result in undesirable affective states, such as frustration and demotivation, decreasing their performance and potentially leading to increasing dropout rates. Recently, new research emerged on systems to recommend problems in POJs; however, the data collection for these approaches was not fine-grained; importantly, they did not take into consideration the students' previous effort and achievement. Thus, this study proposes for the first time a prescriptive analytics solution for students' programming behaviour by constructing and evaluating an automatic recommender module based on students' effort, to personalise the problems presented to the learner in POJs. The aim is to improve the learners achievement, whilst minimising negative affective states in CS1 courses. Results in a within-subject double-blind controlled experiment showed that our method significantly improved positive affective states, whilst minimising the negatives ones. Moreover, our recommender significantly increased students' achievement (correct solutions) and reduced dropout and failure in problem-solving.

Millions of people have enrolled and enrol (especially in the Covid-19 pandemic world) in MOOCs. However, the retention rate of learners is notoriously low. The majority of the research work on this issue focuses on predicting the dropout rate, but very few use explainable learning patterns as part of this analysis. However, visual representation of learning patterns could provide deeper insights into learners' behaviour across different courses, whilst numerical analyses canand arguably, shouldbe used to confirm the latter. Thus, this paper proposes and compares different granularity visualisations for learning patterns (based on clickstream data) for both course completers and noncompleters. In the large-scale MOOCs we analysed, across various domains, our fine-grained, fish-eye visualisation approach showed that non-completers are more likely to jump forward in their learning sessions, often on a 'catch-up' path, whilst completers exhibit linear behaviour. For coarser, bird-eye granularity visualisation, we observed learners' transition between types of learning activity, obtaining typed transition graphs. The results, backed up by statistical significance analysis and machine learning, provide insights for course instructors to maintain engagement of learners by adapting the course design to not just 'dry' predicted values, but explainable, visually viable paths extracted.