Many techniques have been developed over the years to automatically find bugs in software. Often, these techniques rely on formal methods and sophisticated program analysis. While these techniques are valuable, they can be difficult to apply, and they aren’t always effective in finding real bugs. Bug patterns are code idioms that are often errors. We have implemented automatic detectors for a variety of bug patterns found in Java programs. In this paper, we describe how we have used bug pattern detectors to find real bugs in several real-world Java applications and libraries. We have found that the effort required to implement a bug pattern detector tends to be low, and that even extremely simple detectors find bugs in real applications. From our experience applying bug pattern detectors to real programs, we have drawn several interesting conclusions. First, we have found that even well tested code written by experts contains a surprising number of obvious bugs. Second, Java (and similar languages) have many language features and APIs which are prone to misuse. Finally, that simple automatic techniques can be effective at countering the impact of both ordinary mistakes and misunderstood language features. 1.

This study describes how elementary school students search for and select books using a digital library. This work was done as part of the International Children’s Digital Library (ICDL) project in order to explore and discover new directions for the development of digital library interfaces for children ages 3-13. Children used two versions of the ICDL software to search for, select, and read books. We performed a frequency analysis of the number of queries run, books selected, and books opened, and compared book selection rates and book opening rates. Popular query categories and titles selected are tallied. We found differences in book

Because threads are a core feature of the Java language, the widespread adoption of Java has exposed a much wider audience to concurrency than previous languages have. Concurrent programs are notoriously di#cult to write correctly, and many subtle bugs can result from incorrect use of threads and synchronization. Therefore, finding techniques to find concurrency bugs is an important problem.

Elementary-age children are among the largest user groups of computers and the Internet, so it is important to design searching and browsing tools that support them. However, many interfaces for children do not consider their skills and preferences. Children are capable of doing Boolean searches, but have difficulty with the sequential presentation of hierarchical structures used in many

Abstract. An advanced interface is presented for fluid interaction in a personal digital library system. The system employs a zoomable planar representation of a collection using hybrid continuous/quantum treemap visualizations to facilitate navigation while minimizing cognitive load. The system is particularly well suited to user tasks which, in the physical world, are normally carried out by laying out a set of related documents on a physical desk — namely, those tasks that require frequent and rapid transfer of attention from one document in the collection to another. Discussed are the design and implementation of the system as well as its relationship to previous work. 1

Children are among the fastest growing groups of users of the Internet, so it is important to design searching and browsing interfaces, such as those found in digital libraries, to support them. However, many interfaces geared toward elementary-age children suffer from at least one of two common problems. First, many assume that young users can spell, type, read, navigate, compose queries, and/or select small objects. Second, many assume that children search for books using the same criteria as adults. In fact, children have difficulty using and understanding traditional interface tools, and often employ different searching and browsing strategies from adults. A number of researchers have created digital libraries that better support young children. Our lab has also focused on this goal, most recently with the International Children’s Digital Library (ICDL) project. This paper elaborates on the reasons why children require different searching and browsing tools and how interfaces that fail to recognize this lead to frustrating experiences. It describes how the ICDL addresses these issues and a study designed to investigate them further. 1

Libraries can be a critical part of a child’s world. Yet few researchers have investigated the concerns of children and what they can contribute to understanding and designing future new libraries. This paper presents a case study of 12 children who live in one of

Children seek information in order to complete school projects on a wide variety of topics, as well as to support their various leisure activities. Such information can be found in print documents, but increasingly young people are turning to the Web to meet their information needs. In order to exploit this resource, however, children must be able to search or browse digital information through the intermediation of an interface. In particular, they must use Webbased portals that in most cases have been designed for adult users. Guidelines for interface design are not hard to fi nd, but typically they also postulate adult rather than juvenile users. The authors discuss their own research work that has focused upon what young people themselves have to say about the design of portal interfaces. They conclude that specifi c interface design guidelines are required for young users rather than simply relying upon general design guidelines, and that in order to formulate such guidelines it is necessary to actively include the young people themselves in this process.

Techniques and tools exist to allow children to create and share stories. However, challenges can arise when attempting to share stories across languages and cultures. In this paper we explore a novel approach to crosslanguage communication. Rather than work with natural language translation tools, we successfully explored the use of images in attempting to communicate a concept across the language barrier, and be able to confirm that the concept has been properly understood. Our initial exploration is framed within the context of a word guessing game, and shows that such an image-based exchange can allow cross-language communication.