An Intelligent Tutoring System for Computer Numerical Control

In recent years, the use of Intelligent Tutoring Systems (ITS) in classrooms and communities has increased and they proved to be very effective. For the domain of Computer Numerical Control (CNC), however, existing approaches in ITS are not applicable or will not work well. CNC programming is different from computer programming languages, and students fail to solve CNC programming problems mainly due to two reasons: (1) lack of problem solving skills and (2) misconceptions or missing facts. CNC programming requires that students master a lot of facts and concepts before they try to write a program. We built an ITS for CNC called the “CNC-Tutor” and proposed a data-driven approach that can generate proper hints and feedback during the students’ problem solving process. This approach is based on finding the most similar past submissions with the current student’s solution. The similarity is measured by the proposed “Behavior & Machine state distance” metric. Experiments show that the generated hints can help the students solve the CNC programming problem and the generated feedback can help the students to find their misconceptions. A survey on the effectiveness of our CNC-Tutor shows a positive impact on the students

Hint generation in programming tutors

Programming is increasingly recognized as a useful and important skill. Online programming courses that have appeared in the past decade have proven extremely popular with a wide audience. Learning in such courses is however not as effective as working directly with a teacher, who can provide students with immediate relevant feedback. The field of intelligent tutoring systems seeks to provide such feedback automatically. Traditionally, tutors have depended on a domain model defined by the teacher in advance. Creating such a model is a difficult task that requires a lot of knowledgeengineering effort, especially in complex domains such as programming. A potential solution to this problem is to use data-driven methods. The idea is to build the domain model by observing how students have solved an exercise in the past. New students can then be given feedback that directs them along successful solution paths. Implementing this approach is particularly challenging for programming domains, since the only directly observable student actions are not easily interpretable. We present two novel approaches to creating a domain model for programming exercises in a data-driven fashion. The first approach models programming as a sequence of textual rewrites, and learns rewrite rules for transforming programs. With these rules new student-submitted programs can be automatically debugged. The second approach uses structural patterns in programs’ abstract syntax trees to learn rules for classifying submissions as correct or incorrect. These rules can be used to find erroneous parts of an incorrect program. Both models support automatic hint generation. We have implemented an online application for learning programming and used it to evaluate both approaches. Results indicate that hints generated using either approach have a positive effect on student performance

A conceptual framework for an affective tutoring system using unobtrusive affect sensing for enhanced tutoring outcomes

PhD ThesisAffect plays a pivotal role in influencing the student’s motivation and learning achievements. The ability of expert human tutors to achieve enhanced learning outcomes is widely attributed to their ability to sense the affect of their tutees and to continually adapt their tutoring strategies in response to the dynamically changing affect throughout the tutoring session. In this thesis, I explore the feasibility of building an Affective Tutoring System (ATS) which senses the student’s affect on a moment-to-moment basis with the use of unobtrusive sensors in the context of computer programming tutoring. The novel use of keystrokes and mouse clicks for affect sensing is proposed here as they are ubiquitous and unobtrusive. I first establish the viability of using keystrokes and contextual logs for affect sensing first on a per exercise session level and then on a more granular basis of 30 seconds. Subsequently, I move on to investigate the use of multiple sensing channels e.g. facial, keystrokes, mouse clicks, contextual logs and head postures to enhance the availability and accuracy of sensing. The results indicated that it is viable to use keystrokes for affect sensing. In addition, the combination of multiple sensor modes enhances the accuracy of affect sensing. From the results, the sensor modes that are most significant for affect sensing are the head postures and facial modes. Nevertheless, keystrokes make up for the periods of unavailability of the former. With the affect sensing (both sensing of frustration and disengagement) in place, I moved on to architect and design the ATS and conducted an experimental study and a series of focus group discussions to evaluate the ATS. The results showed that the ATS is rated positively by the participants for usability and acceptance. The ATS is also effective in enhancing the learning of the studentsNanyang Polytechni

Metric Learning for Structured Data

Paaßen B. Metric Learning for Structured Data. Bielefeld: Universität Bielefeld; 2019.Distance measures form a backbone of machine learning and information retrieval in many application fields such as computer vision, natural language processing, and biology. However, general-purpose distances may fail to capture semantic particularities of a domain, leading to wrong inferences downstream. Motivated by such failures, the field of metric learning has emerged. Metric learning is concerned with learning a distance measure from data which pulls semantically similar data closer together and pushes semantically dissimilar data further apart. Over the past decades, metric learning approaches have yielded state-of-the-art results in many applications. Unfortunately, these successes are mostly limited to vectorial data, while metric learning for structured data remains a challenge. In this thesis, I present a metric learning scheme for a broad class of sequence edit distances which is compatible with any differentiable cost function, and a scalable, interpretable, and effective tree edit distance learning scheme, thus pushing the boundaries of metric learning for structured data. Furthermore, I make learned distances more useful by providing a novel algorithm to perform time series prediction solely based on distances, a novel algorithm to infer a structured datum from edit distances, and a novel algorithm to transfer a learned distance to a new domain using only little data and computation time. Finally, I apply these novel algorithms to two challenging application domains. First, I support students in intelligent tutoring systems. If a student gets stuck before completing a learning task, I predict how capable students would proceed in their situation and guide the student in that direction via edit hints. Second, I use transfer learning to counteract disturbances for bionic hand prostheses to make these prostheses more robust in patients' everyday lives

First CLIPS Conference Proceedings, volume 2

The topics of volume 2 of First CLIPS Conference are associated with following applications: quality control; intelligent data bases and networks; Space Station Freedom; Space Shuttle and satellite; user interface; artificial neural systems and fuzzy logic; parallel and distributed processing; enchancements to CLIPS; aerospace; simulation and defense; advisory systems and tutors; and intelligent control