| 1. |
- Azhar, Damir, et al.
(author)
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Using ensembles for web effort estimation
- 2013
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Conference paper (peer-reviewed)abstract
- Background: Despite the number of Web effort estimation techniques investigated, there is no consensus as to which technique produces the most accurate estimates, an issue shared by effort estimation in the general software estimation domain. A previous study in this domain has shown that using ensembles of estimation techniques can be used to address this issue. Aim: The aim of this paper is to investigate whether ensembles of effort estimation techniques will be similarly successful when used on Web project data. Method: The previous study built ensembles using solo effort estimation techniques that were deemed superior. In order to identify these superior techniques two approaches were investigated: The first involved replicating the methodology used in the previous study, while the second approach used the Scott-Knott algorithm. Both approaches were done using the same 90 solo estimation techniques on Web project data from the Tukutuku dataset. The replication identified 16 solo techniques that were deemed superior and were used to build 15 ensembles, while the Scott-Knott algorithm identified 19 superior solo techniques that were used to build two ensembles. Results: The ensembles produced by both approaches performed very well against solo effort estimation techniques. With the replication, the top 12 techniques were all ensembles, with the remaining 3 ensembles falling within the top 17 techniques. These 15 effort estimation ensembles, along with the 2 built by the second approach, were grouped into the best cluster of effort estimation techniques by the Scott-Knott algorithm. Conclusion: While it may not be possible to identify a single best technique, the results suggest that ensembles of estimation techniques consistently perform well even when using Web project data
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| 2. |
- Britto, Ricardo, et al.
(author)
-
A Specialized Global Software Engineering Taxonomy for Effort Estimation
- 2016
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In: International Conference on Global Software Engineering. - : IEEE Computer Society. - 9781509026807 ; , s. 154-163
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Conference paper (peer-reviewed)abstract
- To facilitate the sharing and combination of knowledge by Global Software Engineering (GSE) researchers and practitioners, the need for a common terminology and knowledge classification scheme has been identified, and as a consequence, a taxonomy and an extension were proposed. In addition, one systematic literature review and a survey on respectively the state of the art and practice of effort estimation in GSE were conducted, showing that despite its importance in practice, the GSE effort estimation literature is rare and reported in an ad-hoc way. Therefore, this paper proposes a specialized GSE taxonomy for effort estimation, which was built on the recently proposed general GSE taxonomy (including the extension) and was also based on the findings from two empirical studies and expert knowledge. The specialized taxonomy was validated using data from eight finished GSE projects. Our effort estimation taxonomy for GSE can help both researchers and practitioners by supporting the reporting of new GSE effort estimation studies, i.e. new studies are to be easier to identify, compare, aggregate and synthesize. Further, it can also help practitioners by providing them with an initial set of factors that can be considered when estimating effort for GSE projects.
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| 3. |
- Britto, Ricardo, et al.
(author)
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A TAXONOMY OF WEB EFFORT PREDICTORS
- 2017
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In: Journal of Web Engineering. - : Rinton Press. - 1540-9589 .- 1544-5976. ; 16:7-8, s. 541-570
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Journal article (peer-reviewed)abstract
- Web engineering as a field has emerged to address challenges associated with developing Web applications. It is known that the development of Web applications differs from the development of non-Web applications, especially regarding some aspects such as Web size metrics. The classification of existing Web engineering knowledge would be beneficial for both practitioners and researchers in many different ways, such as finding research gaps and supporting decision making. In the context of Web effort estimation, a taxonomy was proposed to classify the existing size metrics, and more recently a systematic literature review was conducted to identify aspects related to Web resource/effort estimation. However, there is no study that classifies Web predictors (both size metrics and cost drivers). The main objective of this study is to organize the body of knowledge on Web effort predictors by designing and using a taxonomy, aiming at supporting both research and practice in Web effort estimation. To design our taxonomy, we used a recently proposed taxonomy design method. As input, we used the results of a previously conducted systematic literature review (updated in this study), an existing taxonomy of Web size metrics and expert knowledge. We identified 165 unique Web effort predictors from a final set of 98 primary studies; they were used as one of the basis to design our hierarchical taxonomy. The taxonomy has three levels, organized into 13 categories. We demonstrated the utility of the taxonomy and body of knowledge by using examples. The proposed taxonomy can be beneficial in the following ways: i) It can help to identify research gaps and some literature of interest and ii) it can support the selection of predictors for Web effort estimation. We also intend to extend the taxonomy presented to also include effort estimation techniques and accuracy metrics.
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| 4. |
- Britto, Ricardo, 1982-, et al.
(author)
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An Empirical Investigation on Effort Estimation in Agile Global Software Development
- 2015
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In: Proceedings of the 2015 IEEE 10th International Conference on Global Software Engineering. - 9781479984091 ; , s. 38-45
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Conference paper (peer-reviewed)abstract
- Effort estimation is a project management activity that is mandatory for the execution of softwareprojects. Despite its importance, there have been just a few studies published on such activities within the Agile Global Software Development (AGSD) context. Their aggregated results were recently published as part of a secondary study that reported the state of the art on effort estimationin AGSD. This study aims to complement the above-mentioned secondary study by means of anempirical investigation on the state of the practice on effort estimation in AGSD. To do so, a survey was carried out using as instrument an on-line questionnaire and a sample comprising softwarepractitioners experienced in effort estimation within the AGSD context. Results show that the effortestimation techniques used within the AGSD and collocated contexts remained unchanged, with planning poker being the one employed the most. Sourcing strategies were found to have no or a small influence upon the choice of estimation techniques. With regard to effort predictors, globalchallenges such as cultural and time zone differences were reported, in addition to factors that are commonly considered in the collocated context, such as team experience. Finally, many challenges that impact the accuracy of the effort estimates were reported by the respondents, such as problems with the software requirements and the fact that the communication effort between sites is not properly accounted.
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| 5. |
- Britto, Ricardo, et al.
(author)
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An Extended Global Software Engineering Taxonomy
- 2016
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In: Journal of Software Engineering Research and Development. - : Springer. - 2195-1721. ; 4:3
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Journal article (peer-reviewed)abstract
- In Global Software Engineering (GSE), the need for a common terminology and knowledge classification has been identified to facilitate the sharing and combination of knowledge by GSE researchers and practitioners. A GSE taxonomy was recently proposed to address such a need, focusing on a core set of dimensions; however its dimensions do not represent an exhaustive list of relevant GSE factors. Therefore, this study extends the existing taxonomy, incorporating new GSE dimensions that were identified by means of two empirical studies conducted recently.
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| 6. |
- Britto, Ricardo, 1982-, et al.
(author)
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Effort Estimation in Agile Global Software Development Context
- 2014
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In: Agile Methods. Large-Scale Development, Refactoring, Testing, and Estimation. - Cham : Springer. - 9783319143583 ; , s. 182-192
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Conference paper (peer-reviewed)abstract
- Both Agile Software Development (ASD) and Global Software Development (GSD) are 21st century trends in the software industry. Many studies are reported in the literature wherein software companies have applied an agile method or practice GSD. Given that effort estimation plays a remarkable role in software project management, how do companies perform effort estimation when they use agile method in a GSD context? Based on two effort estimation Systematic Literature Reviews (SLR) - one in within the ASD context and the other in a GSD context, this paper reports a study in which we combined the results of these SLRs to report the state of the art of effort estimation in agile global software development (ASD) context.
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| 7. |
- Britto, Ricardo, 1982-, et al.
(author)
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Effort Estimation in Global Software Development: A systematic Literature Review
- 2014
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In: Proceedings of the 2014 9th IEEE International Conference on Global Software Engineering. - 9781479943609 ; , s. 135-144
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Conference paper (peer-reviewed)abstract
- Nowadays, software systems are a key factor in the success of many organizations as in most cases they play a central role helping them attain a competitive advantage. However, despite their importance, software systems may be quite costly to develop, so substantially decreasing companies’ profits. In order to tackle this challenge, many organizations look for ways to decrease costs and increase profits by applying new software development approaches, like Global Software Development (GSD). Some aspects of the software project like communication, cooperation and coordination are more chal- lenging in globally distributed than in co-located projects, since language, cultural and time zone differences are factors which can increase the required effort to globally perform a software project. Communication, coordination and cooperation aspects affect directly the effort estimation of a project, which is one of the critical tasks related to the management of a software development project. There are many studies related to effort estimation methods/techniques for co-located projects. However, there are evidences that the co-located approaches do not fit to GSD. So, this paper presents the results of a systematic literature review of effort estimation in the context of GSD, which aimed at help both researchers and practitioners to have a holistic view about the current state of the art regarding effort estimation in the context of GSD. The results suggest that there is room to improve the current state of the art on effort estimation in GSD.
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| 8. |
- Dallora Moraes, Ana Luiza, et al.
(author)
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A decision tree multifactorial approach for predicting dementia in a 10 years’ time
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Other publication (other academic/artistic)abstract
- Background: Dementia is a complex neurological disorder, to which little is known about its mechanisms and no therapeutic treatment was identified, to date, to revert or alleviate its symptoms. It affects the older adults population causing a progressive cognitive decline that can become severe enough to impair the individuals' independence and functioning. In this scenario, the prognosis research, directed to identify modifiable risk factors in order to delay or prevent its development, in a big enough time frame is substantially important.Objective: This study investigates a decision tree multifactorial approach for the prognosis of dementia of individuals, not diagnosed with this disorder at baseline, and their development (or not) of dementia in a time frame of 10 years. Methods: This study retrieved data from the Swedish National Study on Aging and Care, which consisted of 726 subjects (313 males and 413 females), of which 91 presented a diagnosis of dementia at the 10-year study mark. A K-nearest neighbors multiple imputation method was employed to handle the missing data. A wrapper feature selection was employed to select the best features in a set of 75 variables, which considered factors related to demographic, social, lifestyle, medical history, biochemical test, physical examination, psychological assessment and diverse health instruments relevant to dementia evaluation. Lastly, a cost-sensitive decision tree approach was employed in order to build predictive models in an stratified nested cross-validation experimental setup.Results: The proposed approach achieved an AUC of 0.745 and Recall of 0.722 for the 10-year prognosis of dementia. Our findings showed that most of the variables selected by the tree are related to modifiable risk factors, of which physical strength was an important factor across all ages of the sample. Also, there was a lack of variables related to the health instruments routinely used for the dementia diagnosis that might not be sensitive enough to predict dementia in a 10 years’ time.Conclusions: The proposed model identified diverse modifiable factors, in a 10 years’ time from diagnosis, that could be investigated for possible interventions in order to delay or prevent the dementia onset.
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| 9. |
- Dallora Moraes, Ana Luiza, et al.
(author)
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Bone age assessment with various machine learning techniques : A systematic literature review and meta-analysis
- 2019
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In: PLOS ONE. - : Public Library of Science. - 1932-6203. ; 14:7
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Research review (peer-reviewed)abstract
- Background The assessment of bone age and skeletal maturity and its comparison to chronological age is an important task in the medical environment for the diagnosis of pediatric endocrinology, orthodontics and orthopedic disorders, and legal environment in what concerns if an individual is a minor or not when there is a lack of documents. Being a time-consuming activity that can be prone to inter- and intra-rater variability, the use of methods which can automate it, like Machine Learning techniques, is of value. Objective The goal of this paper is to present the state of the art evidence, trends and gaps in the research related to bone age assessment studies that make use of Machine Learning techniques. Method A systematic literature review was carried out, starting with the writing of the protocol, followed by searches on three databases: Pubmed, Scopus and Web of Science to identify the relevant evidence related to bone age assessment using Machine Learning techniques. One round of backward snowballing was performed to find additional studies. A quality assessment was performed on the selected studies to check for bias and low quality studies, which were removed. Data was extracted from the included studies to build summary tables. Lastly, a meta-analysis was performed on the performances of the selected studies. Results 26 studies constituted the final set of included studies. Most of them proposed automatic systems for bone age assessment and investigated methods for bone age assessment based on hand and wrist radiographs. The samples used in the studies were mostly comprehensive or bordered the age of 18, and the data origin was in most of cases from United States and West Europe. Few studies explored ethnic differences. Conclusions There is a clear focus of the research on bone age assessment methods based on radiographs whilst other types of medical imaging without radiation exposure (e.g. magnetic resonance imaging) are not much explored in the literature. Also, socioeconomic and other aspects that could influence in bone age were not addressed in the literature. Finally, studies that make use of more than one region of interest for bone age assessment are scarce. Copyright: © 2019 Dallora et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
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| 10. |
- Felizardo, Katia, et al.
(author)
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Defining protocols of systematic literature reviews in software engineering : A survey
- 2017
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In: Proceedings - 43rd Euromicro Conference on Software Engineering and Advanced Applications, SEAA 2017. - : Institute of Electrical and Electronics Engineers Inc.. - 9781538621400 ; , s. 202-209
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Conference paper (peer-reviewed)abstract
- Context: Despite being defined during the first phase of the Systematic Literature Review (SLR) process, the protocol is usually refined when other phases are performed. Several researchers have reported their experiences in applying SLRs in Software Engineering (SE) however, there is still a lack of studies discussing the iterative nature of the protocol definition, especially how it should be perceived by researchers conducting SLRs. Objective: The main goal of this study is to perform a survey aiming to identify: (i) the perception of SE researchers related to protocol definition; (ii) the activities of the review process that typically lead to protocol refinements; and (iii) which protocol items are refined in those activities. Method: A survey was performed with 53 SE researchers. Results: Our results show that: (i) protocol definition and pilot test are the two activities that most lead to further protocol refinements; (ii) data extraction form is the most modified item. Besides that, this study confirmed the iterative nature of the protocol definition. Conclusions: An iterative pilot testcan facilitate refinements in the protocol. © 2017 IEEE.
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