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Data for empirical studies of software engineering can be difficult to obtain. Extrapolations from small controlled experiments to large development environments are tenuous and observation tends to change the behavior of the subjects. In this thesis we propose the use of data gathered from software repositories in observational studies of software engineering. We present tools we have developed to extract data from CVS repositories and the SourceForge Research Archive. We use these tools to gather data from 9,999 Open Source projects. By analyzing these data we are able to provide insights into the structure of Open Source projects. For example, we find that the vast majority of the projects studied have never had more than three contributors and that the vast majority of authors studied have never contributed to more than one project. However, there are projects that have had up to 120 contributors in a single year and authors who have contributed to more than 20 projects which raises interesting questions about team dynamics in the Open Source community. We also use these data to empirically test the belief that productivity is constant in terms of lines of code per programmer per year regardless of the programming language used. We find that yearly programmer productivity is not constant across programming languages, but rather that developers using higher level languages tend to write fewer lines of code per year than those using lower level languages.

Conventional wisdom, inspired in part by Eric Raymond, suggests that open source developers primarily develop software for developers like themselves. In our studies we distinguish between reflexive software (software written primarily for other developers) and irreflexive software (software written primarily for passive users). In the first study, we present four criteria which we then use to assess project reflexivity in SourceForge. These criteria are based on three specific indicators: intended audience, relevant topics, and supported operating systems. Based on our criteria, we find that 68% of SourceForge projects are reflexive (in the sense described by Raymond). In the second study, we randomly sample and statically estimate reflexivity within SourceForge. Our results support Raymond's assertions that 1) OSS projects tend to be reflexive and 2) reflexive OSS projects tend to be more successful than irreflexive projects. We also find a decrease in reflexivity from a high in 2001 to a low in 2011.

Assigned sex estimation via the greater sciatic notch (GSN) is traditionally performed via physical/visual examination and ordinal scoring; however, this relies on the subjective assessment of morphology for typological classification which may not be reflective of human variation. Three-dimensional (3D) photogrammetry may offer a technologically advanced, low cost, and more objective alternative to assess the complex curvature of anatomical landmarks. This research explores the accuracy of photogrammetry derived 3D models by comparing digital measurements to those obtained from the skeletal elements and to streamline the application of curvature analysis for the estimation of assigned sex from the GSN. This study utilizes the left and right os coxae from 15 skeletal individuals (5 females, 10 males) from the Boston University Chobanian & Avedisian School of Medicine. A Fujifilm X-Pro2 and Fujifilm 35 mm prime lens captured 123 images per element, which were processed in Meshroom by AliceVision® to create a 3D textured mesh. The mesh was exported into Blender for cleanup, scaling, measurement, and curvature analysis. The measurements were between 96.54% and 99.94% consistent across methods and observations. The consistency between digital metric observations increased by an average of 0.07% when compared to the consistency of the dry bone measurements. Additionally, curvature analysis of the GSN correctly estimated the assigned sex of all os coxae in the sample. This study demonstrates that photogrammetry is an accurate and reliable method for the digitization of remains that enables analytical techniques to better capture skeletal variation compared to traditional methods.

Electron-driven processes lie at the core of a large variety of physical, biological, and chemical phenomena. Despite their crucial roles in science and technology, detailed description of these processes remains a significant challenge, and there is a need for the development of accurate and efficient computational tools that enable predictive simulation. This work is focused on the development of novel software tools and methodologies aimed at two classes of electron-mediated processes: (i) electron-molecule scattering, and (ii) charge transfer in proteins. The first major focus of this thesis is the electronic structure of autoionizing electronic resonances. The theoretical description of these metastable states is intractable by means of conventional quantum chemistry techniques, and specialized techniques are required in order to accurately describe their energies and lifetimes. In this work, we have utilized the complex absorbing potential (CAP) method, and describe three developments which have advanced the applicability, efficiency, and accessibility of the CAP methodology for molecular resonances: (1) implementation and investigation of the smooth Voronoi potential (2) implementation of CAP in the projected scheme, and (3) development of the OpenCAP package, which extends the CAP methodology to popular electronic structure packages. The second major focus is the identification of electron and hole transfer (ET) pathways in biomolecules. Both experimental and theoretical inquiries into electron/hole transfer processes in biomolecules generally require targeted approaches, which are complicated by the existence of numerous potential pathways. To this end, we have developed an open-source web platform, eMap, which exploits a coarse-grained model of the protein crystal structure to (1) enable pre-screening of potentially efficient ET pathways, and (2) identify shared pathways/motifs in families of proteins. Following introductory chapters on motivation and theoretical background, we devote a chapter to each new methodology mentioned above. The open-source software tools discussed herein are under active development, and have been utilized in published work by several unaffiliated experimental and theoretical groups across the world. We conclude the dissertation with a summary and discussion of the outlook and future directions of the OpenCAP and eMap software packages.

High quality software is a key component of various technology systems that are crucial to software producers, users, and society in general. Software application development today uses software from external sources, to achieve software implementation goals. Numerous methods, activities, and standards have been developed in order to realize quality software. Nevertheless, the pursuit for new methods of realizing and assuring quality in software is incessant. Researchers in the software engineering field are in pursuit of methods that can be on par with changing technology. Assessment of open-source software can be supported by a methodology that uses data from prior releases of a software product to predict the quality of a future release. The proposed methodology is validated using a case study of MPICH ? an open-source software product from the field of high-performance computing. A quantitative model and a module-order model have been developed that can predict the modules that are expected to have code-churn and the amount of code-churn in each module. Code-churn is defined as the amount of update activity that has been done to a software product in order to fix bugs. Further validation of the proposed methodology on other software and development of classification models for the quality factor code-churn are recommended as future work.

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Kunskap om olika utvecklingsmetoder vid start av ett nytt mjukvaruutvecklingsprojekt äravgörande för utvecklarna, styrorganen och slutprodukten. Därför prioriteras ofta nya ochokända metoder ned för att säkerställa att arbetet blir gjort och att lösningen kommer attlevereras i tid och med hög kvalitet. Detta beteende gör på lång sikt att mjukvaruutvecklingsprojektgår miste om nya och bättre utvecklingsmetoder.För belysa nya utvecklingsmetoder och upplysa de som behöver, valde vi att undersökaskillnaderna i krav framställning inom området Open Source Software(OSS)1-utveckling.I vårt arbete ställer tre forskningsfrågor som ska belysa ämnet dessa bevarar vi genom attutföra en fallstudie. I fallstudien undersöker vi hur och av vilka som krav framställts i ettföretagsstyrt projekt jämfört med ett projekt drivet av en frivilligorganisation.Fallstudien visade att externa användare i frivilligorganisation OSS-projekt har lägredelaktighet, det vill säga bidrag till projektartefakter, jämfört med företagsdrivna projektdär deltagandet av externa användare är högre. Slutligen diskuterar vi implikationerna avresultaten för både OSS-projekt drivna av företag och frivilligorganisationer. Vi kan förbåda styrorganen dra slutsatsen att det är möjligt att öka både utvecklingshastighet ochproduktens värde för kunden. / Knowledge about different development methods when starting up a new software developmentproject is crucial for the developers, the governing bodies and the end product.Therefore new and unfamiliar options are taken out of the equation to make sure that thework gets done and that the solution will be delivered on time and with high quality. Thisbehaviour in the long term does, however, exclude new and better ways of executing thework in the process.To shine light upon new development methods and enlighten those who are in needof insight into a new viable option we chose to investigate the differences in requirementelicitation within the area of Open Source Software development. By examining how andby who requirements are elicited in a firm-driven project compared to a community drivenproject, we framed a total of three research questions to base our case study on.The case study showed that in community driven Open Source Software projects externalusers have low participation, in other words contributions to project artefacts, comparedto firm-driven projects where the participation of external users is high. Finally, wediscuss the potential implications of the findings for both community- and firm-driven OSSprojects. We could conclude for both types that it’s possible to increase both developmentspeed and customer product value.

Publishing software publicly is a new phenomenon for U.S. federal government agencies. In August 2016, the White House issued the Federal Source Code Policy: Achieving Efficiency, Transparency, and Innovation through Reusable and Open Source Software (FSCP). The FSCP mandated Chief Financial Officers (CFO) Act agencies to publish at least 20% of their custom developed code as open source software (OSS). The federal government has the responsibility to account for public spending, including spending for IT. The publication of OSS is one way the public can know about government spending. OSS additionally benefits the public by providing access to code, thus, making it the "People's Code." From 2016 to 2019, the progress of CFO Act agencies in implementing the policy was mixed. This study examines whether and how organizational theoretical variables – cultural beliefs, public engagement, structural dimensions, and organizational location – affect policy implementation. The study uses the publication of OSS as an indicator of effective policy implementation, and it identifies the factors that hinder or aid publishing OSS. Using metadata collected from GitHub's application programming interface (API), I created a sampling frame that included 23 of 24 executive agencies publishing OSS before and after the FSCP was published. From the sampling frame, 25 participants from 20 agencies agreed to participate in the study. These participants were from software development units that minimally, moderately, or frequently published OSS. The sample consisted of participants from units mostly located outside a Chief Information Officer (CIO) office focused on software development and data science activities. Grounded theory provided an approach for data collection with elite interviews and artifact gathering allowing for analysis in an iterative, comparative manner for generating a theory of policy implementation for OSS publication. Units more frequently published OSS when they expressed non-monolithic and advantageous cultural beliefs; practiced more and more varied public engagement through bi-directional communication, events, and electronic tools; had structures with less centralization, more formalization, more differentiation, and more coordination; and were located in the "middle" of organizations with fewer hierarchical layers. Additionally, some units expressed both cautionary and advantageous cultural beliefs suggesting beliefs alone are not enough to allow units to publish OSS. This study contributes to policy, public administration, and organization theory literatures. It enhances scholarship by examining a new phenomenon and aids practitioners by providing implications for consideration when implementing policy. / Doctor of Philosophy / Publishing software and its associated source code for public use is a new phenomenon for U.S. federal government agencies. In August 2016, the White House issued the Federal Source Code Policy: Achieving Efficiency, Transparency, and Innovation through Reusable and Open Source Software (FSCP). The FSCP mandated executive-level agencies to publish at least 20% of their custom developed code as open source software (OSS). OSS is software that can be shared within a community of developers through accompanying licenses hosted in online code sharing platforms. The federal government has the responsibility to account for public spending, including spending for IT. The publication of OSS is one way the public can know about government spending. OSS additionally benefits the public by providing access to code, thus, making it the "People's Code." From 2016 to 2019, the progress of executive branch agencies in implementing the FSCP was mixed. This study examines whether and how organizational factors – cultural beliefs, public engagement, structural dimensions, and organizational location – affect agency policy implementation. The study uses the publication of OSS as an indicator of effective policy implementation, and it identifies the factors that hinder or aid publishing OSS. To arrive at a general understanding of agency efforts at policy implementation, I collected data from GitHub's application programming interface (API) and created a list of 23 of 24 executive-level agencies that published OSS both before and after the FSCP was issued. From these agencies, 25 participants from 20 agencies agreed to participate in the study. These participants were from software development units that minimally, moderately, or frequently published OSS. The sample consisted of participants from units mostly located outside a Chief Information Officer (CIO) office that focused on software development and data science activities. Grounded theory provided an approach for data collection with interviews and document collection, leading to continuous analysis for generating a theory of policy implementation for OSS publication. Units more frequently published OSS when they expressed views complementary to those of their parent organization and held advantageous cultural beliefs; practiced more and more varied public engagement through two-way communication, events, and electronic tools; had structures with less centralization, more formalization, more differentiation, and more coordination; and were located in the "middle" of an organization with fewer hierarchical layers. Additionally, some units expressed both cautionary and advantageous cultural beliefs suggesting beliefs alone are not enough to allow units to publish OSS. This study contributes to policy, public administration, and organization theory literatures. It enhances scholarship by examining a new phenomenon and aids practitioners by providing implications for consideration when implementing policy.

The first part of the work is focused on the history and last trend on library automation and integrated library systems, with specific attention on the italian context. The second part evaluates some possible use of open source software in library and open source diffusion in Italy.The third part analyze Koha, an open source ILS, and its possible application at the University of Ca' Foscari Library System.