Context-Aware Practice Problem Recommendation Using Learners’ Skill Level Navigation Patterns

The use of programming online judges(POJs)has risen dramatically in recent years,owing to the fact that the auto-evaluation of codes during practice motivates students to learn programming.Since POJs have greater number of pro-gramming problems in their repository,learners experience information overload.Recommender systems are a common solution to information overload.Current recommender systems used in e-learning platforms are inadequate for POJ since recommendations should consider learners’current context,like learning goals and current skill level(topic knowledge and difficulty level).To overcome the issue,we propose a context-aware practice problem recommender system based on learners’skill level navigation patterns.Our system initially performs skill level navigation pattern mining to discover frequent skill level navigations in the POJ and tofind learners’learning goals.Collaborativefiltering(CF)and con-tent-basedfiltering approaches are employed to recommend problems in the cur-rent and next skill levels based on frequent skill level navigation patterns.The sequence similarity measure is used tofind the top k neighbors based on the sequence of problems solved by the learners.The experiment results based on the real-world POJ dataset show that our approach considering the learners’cur-rent skill level and learning goals outperforms the other approaches in practice problem recommender systems.

Assistant skill in gastric endoscopic submucosal dissection using a clutch cutter

BACKGROUND A clutch cutter is a scissor-type knife used in endoscopic submucosal dissection(ESD)for gastrointestinal tract tumors.The assistant during the ESD using a clutch cutter(ESD-C)needs to rotate the device and grasp the target tissue appropriately;therefore,the assistant’s skill may affect the technical outcomes of ESD-C.AIM To determine how assistant skill level affected the technical outcomes of gastric ESD-C using an ex vivo porcine training model.METHODS In this pilot study,mock lesions of 15-30 mm in diameter were created in the middle or lower third of the porcine stomach.A total of 32 ESD-C procedures were performed by 16 trainees.Each trainee operator performed two ESD-C procedures;one ESD-C was assisted by an expert(ESD-C-E),and the other was assisted by a non-expert(ESD-C-NE).The total procedure time of the ESD was set as the primary outcome,and en bloc resection rate,complete procedure rate,perforation rate,and each procedure time/speed for mucosal incision or submucosal dissection were set as the secondary outcomes.In addition,we investigated factors associated with the difficulty of ESD including incompletion of ESD procedure,a long procedure time(≥20 min)or intraoperative perforation.RESULTS The median total procedure time of the ESD-C-E was significantly shorter than that of the ESD-C-NE(12.9 min vs 21.9 min,P=0.001).The en bloc resection rate was 100%in both groups.Complete resection rates of the ESD-C-E and ESD-C-NE groups were 100%and 93.8%,respectively.No intraoperative perforation was observed in both groups.In the multivariate analysis,assistant skill was significantly associated with the difficulty of ESD,with the highest odds ratio of 16.5.CONCLUSION Assistance by an expert is an important factor when trainees perform ESD-C procedures.

Reading Developmental Trends in Early Years： The Influence of Word Identification Skills and Target Langauge Oral Ability to Comprehension

Language, reading, and reading-related tasks were administered to 148 children from lower primary （Standard 1, 2, and 3） in Kenyan schools. The aim was to investigate the literacy developmental trends across the years and establish which of the two variables, word identification skills or target language oral proficiency influenced reading comprehension performance. The results indicated that word identification skills independently influenced reading comprehension performance in both standard 2 and standard 3 classes, but target language oral skills did not. Further, the analysis of invented spelling task performance revealed evidence of transfer of alphabetic coding skills of first language to English orthography. The spelling errors reflected letter-sound patterns not found in English orthography. Analysis of the miscues in the spelling task revealed that children rely on first language phonological processes to spell target language unfamiliar words as long the languages have a common alphabetic system.

Developing Students’ Critical Thinking and Discourse Level Writing Skill Through Teachers’ Questions: A Sociocultural Approach

The present study adopts a quantitative design to explore the effects of pre-designed teachers' questions as the mediation tool to scaffold the development of students' critical thinking and their discourse level writing skills in English from a sociocultural perspective. The participants were 39 sophomores from two classes. The results showed that:(1) teachers' questions targeting specific critical thinking skill in the classroom and in after-class conferences, as well as in written homework feedback were effective;(2) students backslid a little while internalizing teachers' questions concerning critical thinking;(3) students improved reliably in terms of local and global coherence in their written production with the help of teachers' questions. The findings indicate that teachers' questions facilitate students' development of critical thinking and enhance their discourse level writing skill.