Specification matching is a way to compare two software components based on descriptions of the components' behaviors. In the context of software reuse and library retrieval, it can help determine whether one component can be substituted for another or how one can be modified to fit the requirements of the other. In the context of object-oriented programming, it can help determine when one type is a behavioral subtype of another. We use formal specifications to describe the behavior of software components, and hence, to determine whether two components match. We give precise definitions of not just exact match, but more relevantly, various flavors of relaxed match. These definitions capture the notions of generalization, specialization, and substitutability of software components. Since our formal specifications are pre- and post-conditions written as predicates in firstorder logic, we rely on theorem proving to determine match and mismatch. We give examples from our impleme...

Software productivity has been steadily increasing over the last 30 years, but not enough to close the gap between the demands placed on the software industry and what the state of the practice can deliver [22,39]; nothing short of an order of magnitude increase in productivity will extricate the software industry from its perennial crisis [39,67]. Several decades of intensive research in software engineering and artificial intelligence left few alternatives but sofware reuse as the (only) realistic approach to bring about the gains of productivity and quality that the software industry needs. In this paper, we discuss the implications of reuse on the production, with an emphasis on the technical challenges. Software reuse involves building software that is reusable by design, and building with reusable software. Software reuse includes reusing both the products of previous software projects, and the processes deployed to produce them, leading to a wide spectrum of reuse approaches, from the building blocks (reusing products) approach on one hand, to the generative or reusable processor (reusing processes) on the other [68]. We discuss the implications of such appproaches on the organization, control, and method of software development and discuss proposed models for their economic analysis. Software reuse benefits from methodologies and tools to: 1) build more readily reusable software, and 2) locate, evaluate, and tailor reusable software, the latter being critical for the building blocks approach. Both sets of issues are discussed in this paper, with a focus on application generators and object-oriented development for the first, and a thorough discussion of retrieval techniques for software components, component composition (or bottom-up design) and transformational systems for the second. We conclude by highlighting areas that, in our opinion, are worthy of further investigation.

Abstract—Software system documentation is almost always expressed informally in natural language and free text. Examples include requirement specifications, design documents, manual pages, system development journals, error logs, and related maintenance reports. We propose a method based on information retrieval to recover traceability links between source code and free text documents. A premise of our work is that programmers use meaningful names for program items, such as functions, variables, types, classes, and methods. We believe that the application-domain knowledge that programmers process when writing the code is often captured by the mnemonics for identifiers; therefore, the analysis of these mnemonics can help to associate high-level concepts with program concepts and vice-versa. We apply both a probabilistic and a vector space information retrieval model in two case studies to trace C++ source code onto manual pages and Java code to functional requirements. We compare the results of applying the two models, discuss the benefits and limitations, and describe directions for improvements.

this document are those of the authors and should not be interpreted as necessarily representing the official policies or endorsements, either expressed or implied, of Wright Laboratory or the U. S. Government. The U. S. Government is authorized to reproduce and distribute reprints for Government purposes notwithstanding any copyright notation thereon. This manuscript is submitted for publication with the understanding that the U. S. Government is authorized to reproduce and distribute reprints for Governmental purposes. Authors' address: School of Computer Science, Carnegie Mellon University, 5000 Forbes Avenue, Pittsburgh, PA 15213; email: amy;wing@cs.cmu.edu. To appear, ACM Transactions on Software Engineering and Methodology (TOSEM), April 1995. Permission to copy without fee all or part of this material is granted provided that the copies are not made or distributed for direct commercial advantage, the ACM copyright notice and the title of the publication and its date appear, and notice is given that copying is by permission of the Association for Computing Machinery. To copy otherwise, or to republish, requires a fee and/or specific permission. c fl 1995 ACM xxxx-xxxx/xx/xxxx-xxxx $xx.xx 2 \Delta A. Moormann Zaremski and J. M. Wing ware libraries successfully, especially as libraries increase in size, is the availability of good tools to organize, navigate through, and retrieve from libraries. Currently many libraries use the file system for their only organization (directories and files) and file system and editor commands for navigation and retrieval. For example, the local ML library is organized with categories of components as directories (e.g., local/lib/Container/, local/lib/Threads/); one uses ls and

An information retrieval technique, latent semantic indexing, is used to automatically identi traceability links from system documentation to program source code. The results of two experiments to identi links in existing software systems (i.e., the LEDA library, and Albergate) are presented. These results are compared with other similar type experimental results of traceability link identification using different types of information retrieval techniques. The method presented proves to give good results by comparison and additionally it is a low cost, highly flexible method to apply with regards to preprocessing and/or parsing of the source code and documentation.

Abstract. The theory of concept (or Galois) lattices provides a simple and formal approach to conceptual clustering. In this paper we present GALOIS, a system that automates and applies this theory. The algorithm utilized by GALOIS to build a concept lattice is incremental and efficient, each update being done in time at most quadratic in the number of objects in the lattice. Also, the algorithm may incorporate background information into the lattice, and through clustering, extend the scope of the theory. The application we present is concerned with information retrieval via browsing, for which we argue that concept lattices may represent major support structures. We describe a prototype user interface for browsing through the concept lattice of a document-term relation, possibly enriched with a thesaurus of terms. An experimental evaluation of the system performed on a medium-sized bibliographic database shows good retrieval performance and a significant improvement after the introduction of background knowledge.

The ability to rapidly locate useful on-line services (e.g. software applications, software components, process models, or service organizations), as opposed to simply useful documents, is becoming increasingly critical in many domains. Current service retrieval technology is, however, notoriously prone to low precision. This paper describes a novel service retrieval approached based on the sophisticated use of process ontologies. Our preliminary evaluations suggest that this approach offers qualitatively higher retrieval precision than existing (keyword and tablebased) approaches without sacrificing recall and computational tractability/scalability.

Concept location identifies parts of a software system that implement a specific concept that originates from the problem or the solution domain. Concept location is a very common software engineering activity that directly supports software maintenance and evolution tasks such as incremental change and reverse engineering. This paper addresses the problem of concept location using an advanced information retrieval method, Latent Semantic Indexing (LSI). LSI is used to map concepts expressed in natural language by the programmer to the relevant parts of the source code. Results of a case study on NCSA Mosaic are presented and compared with previously published results of other static methods for concept location. 1

Technical, cognitive, and social factors inhibit the widespread success of systematic software reuse. Our research is primarily concerned with the cognitive and social challenges faced by software developers: how to motivate them to reuse and how to reduce the difficulty of locating components from a large reuse repository. Our research has explored a new interaction style between software developers and reuse repository systems enabled by information delivery mechanisms. Instead of passively waiting for software developers to explore the reuse repository with explicit queries, information delivery autonomously locates and presents components by using the developers' partially written programs as implicit queries. We have designed

An interface has been implemented for exploring the structure of document sets returned in response to a query. The interface allows a user to find subsets of documents that are especially relevant to the query through interaction with an interactive dendrogram which displays a hierarchical clustering of the documents. Dynamic lists of document titles are interlocked with the dendrogram to provide detail of the clusters being viewed by the user. For efficiency, the interface has been implemented in several parallel and distributed computation environments and has been applied to retrieval of encyclopedia articles and news stories. KEYWORDS Clustering, information retrieval, interfaces. 1. INTRODUCTION Classical information retrieval systems are based on the idea that each document in a collection can be compared to a user's query, scored as to its similarity, and displayed in similarity-sorted order. However, this linear sorting may obscure structure among the documents. For instan...