Abstract not found

The recent advances in Formal Concept Analysis (FCA) together with the major changes faced by modern Information Retrieval (IR) provide new unprecedented challenges and opportunities for FCA-based IR applications. The main advantage of FCA for IR is the possibility of creating a conceptual representation of a given document collection in the form of a document lattice, which may be used both to improve the retrieval of specific items and to drive the mining of the collection’s contents. In this paper, we will examine the best features of FCA for solving IR tasks that could not be easily addressed by conventional systems, as well as the most critical aspects for building FCA-based IR applications. These observations have led to the development of CREDO, a system that allows the user to query Web documents and see retrieval results organized in a browsable concept lattice. This is the second major focus of the paper. We will show that CREDO is especially useful for quickly locating the documents corresponding to the meaning of interest among those retrieved in response to an ambiguous query, or for mining the contents of the documents that reference a given entity. An on-line version of the system is available for testing at

The functionalities of software artifacts are defined by structural and behavioral dependencies. During evolution and maintenance phases of a system, the developer has to be able to understand how these dependencies were defined and how they influence the interaction of the artifacts. The developer must be sure that modifications done in the system will not break its behavior. In the most of the cases, this happens because the dependencies are not documented . We propose to tackle this problem in the context of object oriented classes hierarchies using Concept Analysis. We use different properties about invocations in methods to analyze the dependencies among the hierarchy classes in terms of class behaviour. Based on these results, we show a set of patterns that describe repeated kinds of behavior in class hierarchies. We show the application of these patterns in the specific case of Magnitude hierarchy in Smalltalk.

A key problem during software development and maintenance is to detect and recognize recurring collaborations among software artifacts that are implicit in the code. These collaboration patterns are typically signs of applied idioms, conventions and design patterns during the development of the system, and may entail implicit contracts that should be respected during maintenance, but are not documented explicitly. In this paper we apply Formal Concept Analysis to detect implicit collaboration patterns. Our approach generalizes Antoniol and Tonella one for detecting classical design patterns. We introduce a variation to their algorithm to reduce the computation time of the concepts, a language-independent approach for object-oriented languages, and a post-processing phase in which pattern candidates are filtered out. We identify collaboration patterns in the analyzed applications, match them against libraries of known design patterns, and establish relationships between detected patterns and their nearest neighbours. 1.

www.iam.unibe.ch/∼scg Object-oriented applications are difficult to extend and maintain, due to the presence of implicit dependencies in the inheritance hierarchy. Although these dependencies often correspond to well-known schemas, such as hook and template methods, new unanticipated dependency schemas occur in practice, and can consequently be hard to recognize and detect. To tackle this problem, we have applied Concept Analysis to automatically detect recurring dependency schemas in class hierarchies used in object-oriented applications. In this paper we describe our mapping of OO dependencies to the formal framework of Concept Analysis, we apply our approach to a non-trivial case study, and we report on the kinds of dependencies that are uncovered with this technique. As a result, we show how the discovered dependency schemas correspond not only to good design practices, but also to “bad smells ” in design.

Understanding the internal workings of classes is a key prerequisite to maintaining an object-oriented software system. Unfortunately, classical editing and browsing tools offer mainly linear and textual views of classes and their implementation. These views fail to expose the semantic relationships between the internal parts of a class. We propose XRay views ---a technique based on Concept Analysis--- which reveal the internal relationships between groups of methods and attributes of a class. XRay views are composed out of elementary collaborations between attributes and methods, and help the engineer to build a mental model of how a class works internally. In this paper we present XRay views, and illustrate the approach by applying it on the Smalltalk class UIBuilder.

What we propose here is to reduce the size of Galois lattices still conserving their formal structure and exhaustivity. For that purpose we use a preliminary partition of the instance set, representing the association of a "type" to each instance. By redefining the notion of extent of a term in order to cope, to a certain degree (denoted as #), with this partition, we define a particular family of Galois lattices denoted as Alpha Galois lattices. We also discuss the related implication rules defined as inclusion of such #-extents and show that Iceberg concept lattices are Alpha Galois lattices where the partition is reduced to one single class.

Abstract. The Galois Sub-hierarchy (GSH) is a polynomial-size representation of a concept lattice which has been applied to several fields, such as software engineering and linguistics. In this paper, we analyze the performances, in terms of computation time, of three GSH-building algorithms with very different algorithmic strategies: Ares, Ceres and Pluton. We use Java and C++ as implementation languages and Galicia as our development platform. Our results show that implementations in C++ are significantly faster, and that in most cases Pluton is the best algorithm. Keywords: Galois Sub-hierarchy, AOC-Poset, Performance Analysis. 1

Understanding the internal workings of classes is a key prerequisite to maintaining an object-oriented software system. Unfortunately, classical editing and browsing tools offer mainly linear and textual views of classes and their implementation. These views fail to expose the semantic relationships between the internal parts of a class. We propose XRay views ---a technique based on Concept Analysis--- which reveal the internal relationships between groups of methods and attributes of a class. XRay views are composed out of elementary collaborations between attributes and methods and help the engineer to build a mental model of how a class works internally. In this paper we present XRay views, and illustrate the approach by applying it to three Smalltalk classes: OrderedCollection, Scanner, and UIBuilder.

We present a user interface, the OntoRefiner system, for helping the user to navigate numerous retrieved documents after a search querying a semantic portal which integrates a very important number of documents. Retrieved answers are filtered and the user could be provided only with the answers which are, according to him, the most relevant. The refinement process is based on two technologies, dynamic clustering close to Galois lattice structure combined to the use of a domain ontology. The Galois lattice structure provides a sound basis for the query refinement process. However, its construction as a whole is a very costly process. So, we propose an approach based on the use of a domain ontology, avoiding the construction of the whole Galois lattice. In the paper, we present the algorithm and experimental results.