Extending web-based educational systems with personalised support through User Centred Designed recommendations along the e-learning life cycle

In this paper we address an open key issue during the development of web-based educational systems. In particular, we provide an educational-oriented approach for building personalised e-learning environments that focuses on putting the learners' needs in the centre of the development process. Our approach proposes user centred design methodologies involving interdisciplinary teams of software developers and domain experts. It is illustrated in an adaptive e-learning system, where a MOOC (Massive Open Online Course) was taken by nearly 400 learners. In particular, we report where user centred design methods can be applied along the e-learning life cycle to designing and evaluating personalisation support through recommendations in learning management systems.     

The importance of task analysis in Usability Context Analysis - designing for fitness for purpose

Usability Context Analysis (UCA) suggests the use of task analysis in order to characterize the user's requirements of a product. This paper shows that a task analysis is a necessary (but not sufficient) part of a usability context analysis. Further, it is argued that it is necessary to carry out the task analysis to sufficient depth to establish fitness for purpose of the product under test. In addition, the analyst should have some knowledge of the application domain so that from various task sequences, that giving the best user-product task match can be used. The paper indicates by using an example of an echosounder that discrepancies of use can be highlighted through this task-based approach to usability context analysis.     

Efficient Adaptive-Support Association Rule Mining for Recommender Systems

Collaborative recommender systems allow personalization for e-commerce by exploiting similarities and dissimilarities among customers' preferences. We investigate the use of association rule mining as an underlying technology for collaborative recommender systems. Association rules have been used with success in other domains. However, most currently existing association rule mining algorithms were designed with market basket analysis in mind. Such algorithms are inefficient for collaborative recommendation because they mine many rules that are not relevant to a given user. Also, it is necessary to specify the minimum support of the mined rules in advance, often leading to either too many or too few rules; this negatively impacts the performance of the overall system. We describe a collaborative recommendation technique based on a new algorithm specifically designed to mine association rules for this purpose. Our algorithm does not require the minimum support to be specified in advance. Rather, a target range is given for the number of rules, and the algorithm adjusts the minimum support for each user in order to obtain a ruleset whose size is in the desired range. Rules are mined for a specific target user, reducing the time required for the mining process. We employ associations between users as well as associations between items in making recommendations. Experimental evaluation of a system based on our algorithm reveals performance that is significantly better than that of traditional correlation-based approaches.     

教育数据挖掘研究进展

教育数据挖掘(Educational Data Mining,EDM)是一门涉及计算机科学、教育学、统计学的交叉学科。它致力于探索来自教育环境的独特数据,其目的是更好地了解学生及其学习环境,从而提高教育成效。为了深入分析EDM的研究进展,从Web of Science库相关文献、国内外研究现状对EDM进行了系统性梳理,介绍了EDM的工作流程,把数据挖掘技术在教育领域的应用归纳为4类,对处于快速发展阶段的一些EDM典型案例进行了统计分析并讨论了其不足与发展趋势。     

Recommender Systems Research: A Connection-Centric Survey

Recommender systems attempt to reduce information overload and retain customers by selecting a subset of items from a universal set based on user preferences. While research in recommender systems grew out of information retrieval and filtering, the topic has steadily advanced into a legitimate and challenging research area of its own. Recommender systems have traditionally been studied from a content-based filtering vs. collaborative design perspective. Recommendations, however, are not delivered within a vacuum, but rather cast within an informal community of users and social context. Therefore, ultimately all recommender systems make connections among people and thus should be surveyed from such a perspective. This viewpoint is under-emphasized in the recommender systems literature. We therefore take a connection-oriented perspective toward recommender systems research. We posit that recommendation has an inherently social element and is ultimately intended to connect people either directly as a result of explicit user modeling or indirectly through the discovery of relationships implicit in extant data. Thus, recommender systems are characterized by how they model users to bring people together: explicitly or implicitly. Finally, user modeling and the connection-centric viewpoint raise broadening and social issues—such as evaluation, targeting, and privacy and trust—which we also briefly address.     

基于项目分类和用户群体兴趣的协同过滤算法

由于用户评分数据在极端稀疏的情况下会导致传统协同过滤算法的推荐质量下降,针对该问题,提出一种基于项目分类和用户群体兴趣的协同过滤算法。该算法根据项目类别信息对项目进行分类,相同分类的项目具有较高的相似性;利用评分数据计算各个项目分类上的用户相似性矩阵,并计算用户群体在各个分类上的兴趣,通过二者构造加权的用户相似性矩阵;利用用户加权相似性矩阵寻找用户的最近邻以获得最佳的推荐效果。实验结果表明,该算法能有效提高推荐质量。     

E-Commerce Recommendation Applications

Recommender systems are being used by an ever-increasing number of E-commerce sites to help consumers find products to purchase. What started as a novelty has turned into a serious business tool. Recommender systems use product knowledge—either hand-coded knowledge provided by experts or mined knowledge learned from the behavior of consumers—to guide consumers through the often-overwhelming task of locating products they will like. In this article we present an explanation of how recommender systems are related to some traditional database analysis techniques. We examine how recommender systems help E-commerce sites increase sales and analyze the recommender systems at six market-leading sites. Based on these examples, we create a taxonomy of recommender systems, including the inputs required from the consumers, the additional knowledge required from the database, the ways the recommendations are presented to consumers, the technologies used to create the recommendations, and the level of personalization of the recommendations. We identify five commonly used E-commerce recommender application models, describe several open research problems in the field of recommender systems, and examine privacy implications of recommender systems technology.     

用于推荐系统聚类分析的用户兴趣度研究

根据推荐系统对用户（商品）聚类的要求,探讨采用用户（网页）兴趣度进行聚类分析的合理思想。通过用户浏览时间、浏览行为以及网页信息量差异等因素的对比,得出用户对某类商品的兴趣度计算方法。借助阈值的设定,定义了用户感兴趣的商品集、商品的感兴趣用户集和兴趣相似的用户集,得到了基于用户兴趣度的用户聚类的一般过程,具有一定的推广价值和借鉴意义。     

改进的哈希学习高效推荐算法

哈希技术能有效地解决推荐系统面临的存储和检索效率的问题.然而,现存的哈希推荐方法存在一个问题,推荐关注于建模用户对项目的偏好,而哈希学习关心的是相似性.为此,提出了一种改进的哈希推荐方法.计算每个用户、项目相对评分系统的均值作为偏置.对用户评分矩阵进行去偏置处理,将评分映射到相似性区间.以保持相似性为目标,提出了两种方...     

用户访问兴趣路径挖掘方法

针对当前挖掘用户访问模式算法仅将频繁访问路径作为用户浏览兴趣路径的问题,依据使用Web日志挖掘用户兴趣页面时,通过引入页面信息量参数,综合考虑页面访问次数、浏览时间和页面信息量大小来定义用户兴趣度,提出了基于兴趣度的用户访问模式挖掘算法。实验证明该算法是有效的,在用户浏览兴趣度量方面比当前的频繁访问路径挖掘算法更准确。     

User Modeling for Adaptive News Access

We present a framework for adaptive news access, based on machine learning techniques specifically designed for this task. First, we focus on the system's general functionality and system architecture. We then describe the interface and design of two deployed news agents that are part of the described architecture. While the first agent provides personalized news through a web-based interface, the second system is geared towards wireless information devices such as PDAs (personal digital assistants) and cell phones. Based on implicit and explicit user feedback, our agents use a machine learning algorithm to induce individual user models. Motivated by general shortcomings of other user modeling systems for Information Retrieval applications, as well as the specific requirements of news classification, we propose the induction of hybrid user models that consist of separate models for short-term and long-term interests. Furthermore, we illustrate how the described algorithm can be used to address an important issue that has thus far received little attention in the Information Retrieval community: a user's information need changes as a direct result of interaction with information. We empirically evaluate the system's performance based on data collected from regular system users. The goal of the evaluation is not only to understand the performance contributions of the algorithm's individual components, but also to assess the overall utility of the proposed user modeling techniques from a user perspective. Our results provide empirical evidence for the utility of the hybrid user model, and suggest that effective personalization can be achieved without requiring any extra effort from the user.