7 research outputs found
The evolution of the laws of software evolution. A discussion based on a systematic literature review
After more than 40 years of life, software evolution should be considered as a mature field. However, despite
such a long history, many research questions still remain open, and controversial studies about the validity
of the laws of software evolution are common. During the first part of these 40 years the laws themselves
evolved to adapt to changes in both the research and the software industry environments. This process
of adaption to new paradigms, standards, and practices stopped about 15 years ago, when the laws were
revised for the last time. However, most controversial studies have been raised during this latter period.
Based on a systematic and comprehensive literature review, in this paper we describe how and when the
laws, and the software evolution field, evolved. We also address the current state of affairs about the validity
of the laws, how they are perceived by the research community, and the developments and challenges that
are likely to occur in the coming years
Motivators and de-motivators in software process improvement : an empirical study
Software quality problems are a concern for the software engineering community. Software
Process Improvement (SPI) is the most recent and most popular approach adopted to address
this problem. SPI focuses on the processes that develop software in order to deliver
improvements to the product. Despite this popularity of SPI there is insufficient evidence of
its successful impact on software quality. Quality problems in software continue. This has led
to some concern in the industry about the effectiveness of SPI in tackling the problem of
software quality. There is evidence to suggest that SPI does improve software quality.
However, there is also evidence to suggest that SPI is not sufficiently supported by software
practitioners. This lack of support may be one of the reasons why SPI appears to be failing at
tackling the problem of software quality. In this research it is argued that this lack of support
for SPI is caused by companies' inability to manage software practitioners' motivation for SPI
properly. Companies may not be managing software practitioners' motivation for SPI
properly because they may not understand them. There is therefore a need to better
understand what software practitioners'motivations for supporting SPI are.
A review of the literature suggests a set of guidelines that can improve software practitioners'
support for SPI. The literature also suggests four themes that underpin software practitioners'
motivation for SPI. The four themes are SPI managers' perception of the motivators and demotivators
for SPI, software practitioners' motivators, software practitioners' de-motivators
and the differences in software practitioners' motivators and de-motivators. The basis of this
research is that exploring the four themes that underpin software practitioners' motivation for
SPI improves understanding of the factors that influence support for SPI. This knowledge of
the factors that influence support for SPI can then be used to validate and provide an
empirical basis for the literature-suggested guidelines. Thereby improving confidence in the
"-IL iidelines.
The four themes underpinning software practitioners' motivation for SPI are examined
through empirical studies. Findings from these studies suggest that SPI managers perceive
senior managers as not supportive of SPI. They also perceive developers as not enthusiastic
about SPI. The findings also suggest that the key motivators of software practitioners for SPI
are visible support and commitment from senior management and empowerment of
practitioners, whereas the key de-motivators are related to constraints on resources and a
failure to secure practitioners' buy-in for SPI. There are also differences in what motivates
and de-motivates different practitioner groups for SPI and these differences are related to the
jobs that practitioners do. Finally, software practitioners have different perceptions of their
role in SPI, which are related to their software development roles. This suggests that the
objectives of SPI should be tailored to the software development objectives of practitioners in
order to improve their support for SPI.
Overall, findinas from these studies confirm most of the guidelines suggested by the t:,
literature. The confirmed guidelines are offered as insight to improving support for SPI,
which can in turn help to improve the impact of SPI on software quality
Toward a further understanding of object feature binding: a cognitive neuroscience perspective.
The aim of this thesis is to lead to a further understanding of the neural mechanisms underlying object feature binding in the human brain. The focus is on information processing and integration in the visual system and visual shortterm memory. From a review of the literature it is clear that there are three major
competing binding theories, however, none of these individually solves the binding problem satisfactorily. Thus the aim of this research is to conduct behavioural experimentation into object feature binding, paying particular attention to visual short-term memory.
The behavioural experiment was designed and conducted using a within-subjects delayed responset ask comprising a battery of sixty-four composite objects each with three features and four dimensions in each of three conditions (spatial, temporal and spatio-temporal).Findings from the experiment,which focus on spatial and temporal aspects of object feature binding and feature proximity on
binding errors, support the spatial theories on object feature binding, in addition we propose that temporal theories and convergence, through hierarchical feature
analysis, are also involved. Because spatial properties have a dedicated processing neural stream, and temporal properties rely on limited capacity memory systems, memories for sequential information would likely be more
difficult to accuratelyr ecall. Our study supports other studies which suggest that both spatial and temporal coherence to differing degrees,may be involved in
object feature binding. Traditionally, these theories have purported to provide individual solutions, but this thesis proposes a novel unified theory of object feature binding in which hierarchical feature analysis, spatial attention and temporal synchrony each plays a role. It is further proposed that binding takes place in visual short-term memory through concerted and integrated information
processing in distributed cortical areas. A cognitive model detailing this integrated proposal is given. Next, the cognitive model is used to inform the design and suggested implementation of a computational model which would be
able to test the theory put forward in this thesis. In order to verify the model, future work is needed to implement the computational model.Thus it is argued
that this doctoral thesis provides valuable experimental evidence concerning spatio-temporal aspects of the binding problem and as such is an additional building block in the quest for a solution to the object feature binding problem
Embedding requirements within the model driven architecture.
The Model Driven Architecture (MDA) is offered as one way forward in software systems modelling to connect software design with the business domain. The general focus of the MDA is the development of software systems by performing transformations between software design models, and the automatic generation of application code from those models. Software systems are provided by developers, whose
experience and models are not always in line with those of other stakeholders, which presents a challenge for the community. From reviewing the available literature, it is found that whilst many models and notations are available, those that are significantly supported by the MDA may not be best for use by non technical stakeholders. In addition, the MDA does not explicitly consider requirements and specification. This research begins by investigating the adequacy of the MDA requirements phase and examining the
feasibility of incorporating a requirements definition, specifically focusing upon model transformations. MDA
artefacts were found to serve better the software community and requirements were not appropriately integrated within the MDA, with significant extension upstream being required in order to sufficiently accommodate the business user in terms of a requirements definition. Therefore, an extension to the MDA framework is offered that directly addresses Requirements Engineering (RE), including the distinction of
analysis from design, highlighting the importance of specification. This extension is suggested to further the
utility of the MDA by making it accessible to a wider audience upstream, enabling specification to be a direct
output from business user involvement in the requirements phase of the MDA. To demonstrate applicability, this research illustrates the framework extension with the provision of a method and discusses the use of the
approach in both academic and commercial settings. The results suggest that such an extension is academically viable in facilitating the move from analysis into the design of software systems, accessible for business use and beneficial in industry by allowing for the involvement of the client in producing models sufficient enough for use in the development of software systems using MDA tools and techniques
Toward a further understanding of object feature binding : a cognitive neuroscience perspective
The aim of this thesis is to lead to a further understanding of the neural mechanisms underlying object feature binding in the human brain. The focus is on information processing and integration in the visual system and visual shortterm memory. From a review of the literature it is clear that there are three major competing binding theories, however, none of these individually solves the binding problem satisfactorily. Thus the aim of this research is to conduct behavioural experimentation into object feature binding, paying particular attention to visual short-term memory. The behavioural experiment was designed and conducted using a within-subjects delayed responset ask comprising a battery of sixty-four composite objects each with three features and four dimensions in each of three conditions (spatial, temporal and spatio-temporal).Findings from the experiment,which focus on spatial and temporal aspects of object feature binding and feature proximity on binding errors, support the spatial theories on object feature binding, in addition we propose that temporal theories and convergence, through hierarchical feature analysis, are also involved. Because spatial properties have a dedicated processing neural stream, and temporal properties rely on limited capacity memory systems, memories for sequential information would likely be more difficult to accuratelyr ecall. Our study supports other studies which suggest that both spatial and temporal coherence to differing degrees,may be involved in object feature binding. Traditionally, these theories have purported to provide individual solutions, but this thesis proposes a novel unified theory of object feature binding in which hierarchical feature analysis, spatial attention and temporal synchrony each plays a role. It is further proposed that binding takes place in visual short-term memory through concerted and integrated information processing in distributed cortical areas. A cognitive model detailing this integrated proposal is given. Next, the cognitive model is used to inform the design and suggested implementation of a computational model which would be able to test the theory put forward in this thesis. In order to verify the model, future work is needed to implement the computational model.Thus it is argued that this doctoral thesis provides valuable experimental evidence concerning spatio-temporal aspects of the binding problem and as such is an additional building block in the quest for a solution to the object feature binding problem.EThOS - Electronic Theses Online ServiceGBUnited Kingdo