The potential for academic integrity violations increases in online courses and instructors must place extra attention on academic integrity, since cheating techniques and costs are different than in the physical classroom. Although students are less supervised and able to study in a self-paced mode in online learning, unauthorized collaboration is still considered to be a serious integrity violation. However, online learning platforms have the advantage that they may capture detailed timelines of student activity. Analysis of these can enable instructors to detect many patterns of collaboration, e.g., working on assessments together, or copying solutions from unauthorized web pages. In this paper, we describe detection methods for several common patterns of alignment between work timelines of pairs of students, and these patterns' relationship with corroborative evidence such as similar answers and unusually fast completion times. We describe data collection necessary to apply the timeline analysis technique to weekly quiz assessments and project submissions, and discuss the strength of evidence the technique can provide in different situations. We have been applying these techniques in an online project-based course over several years, and it has helped instructors to successfully identify potential cheating cases.

We analyze differences in working habits between well-performing and at-risk students using highly-granular data collected from two semesters of an online project-based, upper-level course on cloud computing at a US institution of higher education. Such differentiating metrics may provide deeper insights than interim grades, which are oftentimes the only quantifiable data that is captured and available to an instructor as a proxy for students' learning. Interim grades provide little insight into students' broader work habits and may mask unsustainable learning strategies that result in shallow learning or quickly-forgotten skills/knowledge. The adoption of technology-enhanced learning tools for course delivery, automatic feedback, and grading enable data-informed insight and reflection into students' working habits. This data could allow the detection of early signs of under-prepared students or students in crisis. We empirically assess what working habits, if any, differ among well-performing and at-risk students. From clickstream and other activity data, we derive 22 metrics such as time spent reading project write-ups, timing of starting and finishing work, or break-taking. We also calculate two measures of consistency of each metric measured by a coefficient of variance and a variance of ranking over the semester as well as outlier behavior of a student. Using Z-test and Kolmogorov-Smirnov test, we confirm differences in multiple behavior patterns. Notably, our data suggest that well-performing students start and finish working on a project earlier than at-risk students but they also tend to have fewer submissions which indicate they are more thoughtful about feedback.

Personalized news recommendation is important to help users find their interested news and improve reading experience.A key problem in news recommendation is learning accurate user representations to capture their interests.Users usually have both long-term preferences and short-term interests.However, existing news recommendation methods usually learn single representations of users, which may be insufficient.In this paper, we propose a neural news recommendation approach which can learn both long-and short-term user representations.The core of our approach is a news encoder and a user encoder.In the news encoder, we learn representations of news from their titles and topic categories, and use attention network to select important words.In the user encoder, we propose to learn long-term user representations from the embeddings of their IDs.In addition, we propose to learn short-term user representations from their recently browsed news via GRU network.Besides, we propose two methods to combine long-term and short-term user representations.The first one is using the long-term user representation to initialize the hidden state of the GRU network in short-term user representation.The second one is concatenating both long-and short-term user representations as a unified user vector.Extensive experiments on a real-world dataset show our approach can effectively improve the performance of neural news recommendation.

News recommendation can help users find interested news and alleviate information overload.The topic information of news is critical for learning accurate news and user representations for news recommendation.However, it is not considered in many existing news recommendation methods.In this paper, we propose a neural news recommendation approach with topic-aware news representations.The core of our approach is a topic-aware news encoder and a user encoder.In the news encoder we learn representations of news from their titles via CNN networks and apply attention networks to select important words.In addition, we propose to learn topic-aware news representations by jointly training the news encoder with an auxiliary topic classification task.In the user encoder we learn the representations of users from their browsed news and use attention networks to select informative news for user representation learning.Extensive experiments on a real-world dataset validate the effectiveness of our approach.

Chuhan Wu, Fangzhao Wu, Mingxiao An, Tao Qi, Jianqiang Huang, Yongfeng Huang, Xing Xie. Proceedings of the 2019 Conference on Empirical Methods in Natural Language Processing and the 9th International Joint Conference on Natural Language Processing (EMNLP-IJCNLP). 2019.

Deep learning techniques have been widely applied to modern recommendation systems, bringing in flexible and effective ways of user representation. Conventionally, user representations are generated purely in the offline stage. Without referencing to the specific candidate item for recommendation, it is difficult to fully capture user preference from the perspective of interest. More recent algorithms tend to generate user representation at runtime, where user's historical behaviors are attentively summarized w.r.t. the presented candidate item. In spite of the improved efficacy, it is too expensive for many real-world scenarios because of the repetitive access to user's entire history. In this work, a novel user representation framework, Hi-Fi Ark, is proposed. With Hi-Fi Ark, user history is summarized into highly compact and complementary vectors in the offline stage, known as archives. Meanwhile, user preference towards a specific candidate item can be precisely captured via the attentive aggregation of such archives. As a result, both deployment feasibility and superior recommendation efficacy are achieved by Hi-Fi Ark. The effectiveness of Hi-Fi Ark is empirically validated on three real-world datasets, where remarkable and consistent improvements are made over a variety of well-recognized baseline methods.

Personalized news recommendation is very important for online news platforms to help users find interested news and improve user experience. News and user representation learning is critical for news recommendation. Existing news recommendation methods usually learn these representations based on single news information, e.g., title, which may be insufficient. In this paper we propose a neural news recommendation approach which can learn informative representations of users and news by exploiting different kinds of news information. The core of our approach is a news encoder and a user encoder. In the news encoder we propose an attentive multi-view learning model to learn unified news representations from titles, bodies and topic categories by regarding them as different views of news. In addition, we apply both word-level and view-level attention mechanism to news encoder to select important words and views for learning informative news representations. In the user encoder we learn the representations of users based on their browsed news and apply attention mechanism to select informative news for user representation learning. Extensive experiments on a real-world dataset show our approach can effectively improve the performance of news recommendation.

News recommendation is very important to help users find interested news and alleviate information overload. Different users usually have different interests and the same user may have various interests. Thus, different users may click the same news article with attention on different aspects. In this paper, we propose a neural news recommendation model with personalized attention (NPA). The core of our approach is a news representation model and a user representation model. In the news representation model we use a CNN network to learn hidden representations of news articles based on their titles. In the user representation model we learn the representations of users based on the representations of their clicked news articles. Since different words and different news articles may have different informativeness for representing news and users, we propose to apply both word- and news-level attention mechanism to help our model attend to important words and news articles. In addition, the same news article and the same word may have different informativeness for different users. Thus, we propose a personalized attention network which exploits the embedding of user ID to generate the query vector for the word- and news-level attentions. Extensive experiments are conducted on a real-world news recommendation dataset collected from MSN news, and the results validate the effectiveness of our approach on news recommendation.