E. Teixeira

Support mechanisms to conduct empirical studies in software engineering: a systematic mapping study

Context: Empirical studies are gaining recognition in the Software Engineering (SE) research community, allowing improved quality of research and accelerating the adoption of new technologies in the software market. However, empirical studies in this area are still limited. In order to foster empirical research in SE, it is essential to understand the resources available to aid these studies. Goal: Identify support mechanisms (methodology, tool, guideline, process, etc.) used to conduct empirical studies in the Empirical Software Engineering (ESE) community. Method: We performed a systematic mapping study that included all full papers published at EASE, ESEM and ESEJ since their first editions. Were selected 891 studies between 1996 and 2013. Results: A total of 375 support mechanisms were identified. We provide the full list of mechanisms and the strategies that uses them. Despite this, we identified a high number of studies that do not cite any mechanism to support their empirical strategies: 433 studies (48%). Experiment is the strategy that has more resources to support their activities. And guideline was the most used type of mechanism. Moreover we observed that the most mechanisms used as reference to empirical studies are not specific to SE area. And some mechanisms were used only in specific activities of empirical research, such as statistical and qualitative data analysis. Experiment and case studies are the strategies most applied. Conclusions: The use of empirical methods in SE has increased over the years. Despite this, many studies did not apply these methods and do not cite any resource to guide their research. Therefore, the list of support mechanisms, where and how they were applied is a major asset to the SE community. Such asset can encourage empirical studies aiding the choice regarding which strategies and mechanisms to use in a research, as well as pointing out examples where they were used, mainly to novice researchers. We also identified new perspectives and gaps that foster other research for the improvement of empirical research in this area.

Threats to validity in controlled experiments in software engineering: what the experts say and why this is relevant

Context: Every experimental study has some threats to validity hindering its results. Goal: Improve software engineering controlled experiments quality by better understanding threats to validity control process. Method: A systematic Survey was executed to collect information from software engineering controlled experiments specialists. Data was quantitative and qualitatively analyzed. Results: 115 researchers took part in the study. Most of them (78.26%) consider extremely important to identify threats to validity during experiments planning to adjust it reducing the probability of threats to validity impacting experiment execution. Conclusions: Results bring participants point of view about identifying controlled experiments threats to validity. However, the study reveals some concerns since a considerable number (18.26%) of participants are not aware of threats to their studies or to new threats raised by actions took to address previous threats, hindering results validity.

Tumor maligno da bainha dos nervos periféricos do pulmão: A propósito de um caso clínico

Resumo Os tumores malignos da bainha dos nervos perifericos correspondem a um grupo raro de sarcomas de tecidos moles que tendem a ocorrer em doentes com neurofibromatose tipo 1 ou varios anos apos tratamentos de radioterapia. A sua localizacao toracica e uma entidade muito rara. A sintomatologia habitual deve-se ao efeito de massa exercido sobre os nervos, podendo persistir durante meses ou anos antes do diagnostico. A escassez de doentes com este tipo de tumor faz com que a abordagem terapeutica ainda permaneca em debate, sendo a cirurgia o procedimento de eleicao. O prognostico destes doentes e mau dada a grande recorrencia local e metastizacao. O caso clinico descrito serve de tema a discussao.

Mioblastoma do pulmão: A propósito de um caso clínico

RESUMO O Mioblastoma de pulmao e um tumor raro, com origem nas celulas de Schwann, cujo modo de apresentacao mais comum e a tosse e a toracalgia. Pode ser um achado radiologico ou endoscopico. O caso que apresentamos referese a um doente de sexo masculino, 55 anos de idade, carpinteiro, exfumador (52 UMA), com historia de bronquite cronica (BC), que referia toracalgia esquerda desde ha alguns meses, ouvindo-se na auscultacao pulmonar um sibilo fixo na base do hemitorax esquerdo. A telerradiografia do torax revelou apenas “paquipleurite residual na base do hemitorax direito”. A TAC toracica (com cortes nnos) mostrou “discreta imagem nodular no apical do lobo inferior esquerdo (B6) e paquipleurite residual na base do hemitorax direito”. A broncofibroscopla revelou “sinais de BC e no segmento mais posterior do apical do lobo inferior esquerdo o esporao esta um pouco esbranquicado mas sem outras lesoes”. Realizou biopsias a este nivel que mostraram “tumor de celulas granulares-Mioblastoma”, pelo que foi submetido a lobectomia inferior esquerda cujo exame anatomopatologico da peca ressecada confirmou o diagnostico. Desde entao, o doente e seguido na nossa consulta mantendo a sua BC controlada e sem qualquer evidencia de recidiva tumoral. A proposito fazem-se algumas consideracoes sobre este tipo de neoplasia do pulmao, cuja histogenese e desconhecida. REV PORT PNEUMOL 2000; VI (4): 323-330