12 research outputs found

    Why and How to Extract Conditional Statements From Natural Language Requirements

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    Functional requirements often describe system behavior by relating events to each other, e.g. "If the system detects an error (e_1), an error message shall be shown (e_2)". Such conditionals consist of two parts: the antecedent (see e_1) and the consequent (e_2), which convey strong, semantic information about the intended behavior of a system. Automatically extracting conditionals from texts enables several analytical disciplines and is already used for information retrieval and question answering. We found that automated conditional extraction can also provide added value to Requirements Engineering (RE) by facilitating the automatic derivation of acceptance tests from requirements. However, the potential of extracting conditionals has not yet been leveraged for RE. We are convinced that this has two principal reasons: 1) The extent, form, and complexity of conditional statements in RE artifacts is not well understood. We do not know how conditionals are formulated and logically interpreted by RE practitioners. This hinders the development of suitable approaches for extracting conditionals from RE artifacts. 2) Existing methods fail to extract conditionals from Unrestricted Natural Language (NL) in fine-grained form. That is, they do not consider the combinatorics between antecedents and consequents. They also do not allow to split them into more fine-granular text fragments (e.g., variable and condition), rendering the extracted conditionals unsuitable for RE downstream tasks such as test case derivation. This thesis contributes to both areas. In Part I, we present empirical results on the prevalence and logical interpretation of conditionals in RE artifacts. Our case study corroborates that conditionals are widely used in both traditional and agile requirements such as acceptance criteria. We found that conditionals in requirements mainly occur in explicit, marked form and may include up to three antecedents and two consequents. Hence, the extraction approach needs to understand conjunctions, disjunctions, and negations to fully capture the relation between antecedents and consequents. We also found that conditionals are a source of ambiguity and there is not just one way to interpret them formally. This affects any automated analysis that builds upon formalized requirements (e.g., inconsistency checking) and may also influence guidelines for writing requirements. Part II presents our tool-supported approach CiRA capable of detecting conditionals in NL requirements and extracting them in fine-grained form. For the detection, CiRA uses syntactically enriched BERT embeddings combined with a softmax classifier and outperforms existing methods (macro-F_1: 82%). Our experiments show that a sigmoid classifier built on RoBERTa embeddings is best suited to extract conditionals in fine-grained form (macro-F_1: 86%). We disclose our code, data sets, and trained models to facilitate replication. CiRA is available at http://www.cira.bth.se/demo/. In Part III, we highlight how the extraction of conditionals from requirements can help to create acceptance tests automatically. First, we motivate this use case in an empirical study and demonstrate that the lack of adequate acceptance tests is one of the major problems in agile testing. Second, we show how extracted conditionals can be mapped to a Cause-Effect-Graph from which test cases can be derived automatically. We demonstrate the feasibility of our approach in a case study with three industry partners. In our study, out of 578 manually created test cases, 71.8% can be generated automatically. Furthermore, our approach discovered 80 relevant test cases that were missed in manual test case design. At the end of this thesis, the reader will have an understanding of (1) the notion of conditionals in RE artifacts, (2) how to extract them in fine-grained form, and (3) the added value that the extraction of conditionals can provide to RE

    Unmet goals of tracking: within-track heterogeneity of students' expectations for

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    Educational systems are often characterized by some form(s) of ability grouping, like tracking. Although substantial variation in the implementation of these practices exists, it is always the aim to improve teaching efficiency by creating homogeneous groups of students in terms of capabilities and performances as well as expected pathways. If students’ expected pathways (university, graduate school, or working) are in line with the goals of tracking, one might presume that these expectations are rather homogeneous within tracks and heterogeneous between tracks. In Flanders (the northern region of Belgium), the educational system consists of four tracks. Many students start out in the most prestigious, academic track. If they fail to gain the necessary credentials, they move to the less esteemed technical and vocational tracks. Therefore, the educational system has been called a 'cascade system'. We presume that this cascade system creates homogeneous expectations in the academic track, though heterogeneous expectations in the technical and vocational tracks. We use data from the International Study of City Youth (ISCY), gathered during the 2013-2014 school year from 2354 pupils of the tenth grade across 30 secondary schools in the city of Ghent, Flanders. Preliminary results suggest that the technical and vocational tracks show more heterogeneity in student’s expectations than the academic track. If tracking does not fulfill the desired goals in some tracks, tracking practices should be questioned as tracking occurs along social and ethnic lines, causing social inequality

    Contraexemplos e raciocĂ­nio dedutivo

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    Tese de Doutoramento apresentada ao ISPA - Instituto UniversitĂĄrioEste trabalho foi desenvolvido com o objectivo de contribuir para uma compreensĂŁo mais alargada do modo como os sujeitos utilizam os contraexemplos no raciocĂ­nio condicional, quando sĂŁo utilizados conteĂșdos que remetem para situaçÔes comuns do quotidiano. NĂŁo existem dĂșvidas de que as pessoas sĂŁo capazes de recuperar contraexemplos, vĂĄrios estudos atestam esta capacidade (e.g. Couto, Quelhas & Juhos, 2010; De Neys & Everaerts, 2008; De Neys, Schaeken & D’ydewalle, 2002; Neys, Schaeken & d'Ydewalle, 2003b;Verschueren, Schaeken, De Neys & d'Ydewalle, 2004). No entanto, a forma como os sujeitos recuperam e utilizam contraexemplos, carece ainda de esclarecimentos. Para cumprir este objectivo geral, construĂ­mos dois conjuntos de experiĂȘncias que incidem em dois factores importantes. Em primeiro lugar investigĂĄmos a recuperação de contraexemplos e aceitação de inferĂȘncias, com avisos e conselhos. Na experiĂȘncia 1, verificĂĄmos que os sujeitos sĂŁo capazes de gerar contraexemplos para ambos os tipos de frase, mas nĂŁo o fazem com igual frequĂȘncia para avisos e conselhos. Em seguida, nas ExperiĂȘncias 2 e 3 investigĂĄmos o impacto da disponibilidade (ExperiĂȘncia 2) e da recuperação (ExperiĂȘncia 3) de contraexemplos, nas inferĂȘncias que os sujeitos fazem, tendo concluĂ­do com alguma surpresa que este impacto Ă© muito pequeno ao contrĂĄrio do que se sabe acontecer com condicionais causais (e.g. Byrne, Espino & Santamaria, 1999; Couto, Quelhas & Juhos, 2010; Cummins, 1995; Cummins, Lubart, Alksnis & Rist, 1991). Ainda no primeiro no conjunto de experiĂȘncias, avaliĂĄmos os padrĂ”es de interpretação que os sujeitos fazem com base nestas condicionais (ExperiĂȘncia 4), tendo concluĂ­do que existe uma variabilidade grande das interpretaçÔes que os sujeitos fazem. No segundo conjunto de experiĂȘncias, recorremos a frases causais para estudar o impacto da recuperação de contraexemplos adicionais. A ExperiĂȘncia 5 demonstra que a recuperação de contraexemplos Ă© um processo pouco fluente e que esta sensação de falta de fluĂȘncia afecta o valor que os sujeitos atribuem aos contraexemplos, conduzindo a um padrĂŁo de supressĂŁo de inferĂȘncias contrĂĄrio Ă  informação que foi recuperada. A ExperiĂȘncia 6 esclarece que o padrĂŁo de supressĂŁo reportado na ExperiĂȘncia 5 se deve Ă s dificuldades de recuperação dos contraexemplos. Quando estes sĂŁo fornecidos aos sujeitos, em vez de recuperados da memĂłria, o padrĂŁo de supressĂŁo corresponde ao conteĂșdo que foi apresentado, ou seja, mais contraexemplos conduzem a maior supressĂŁo. Na ExperiĂȘncia 7 confrontĂĄmos contraexemplos e a frequĂȘncia de ExcepçÔes, tendo concluĂ­do que os sujeitos parecem preferir a informação probabilĂ­stica, Ă  informação que decorre dos contraexemplos. No geral, os nossos resultados mostram trĂȘs factos importantes. Em primeiro lugar que o conhecimento que Ă© recuperado durante o raciocĂ­nio tem diferentes funçÔes para diferentes tipos de condicionais, isto Ă©, os contraexemplos recuperados para Advice tĂȘm uma função diferente dos contraexemplos recuperados para condicionais causais. AlĂ©m disto, mostra ainda que o processo de recuperação de contraexemplos Ă© pouco fluente e as pessoas parecem preferir utilizar a informação probabilĂ­stica. Por fim, esclarece que os dois factores acima mencionados ajudam a explicar as diferenças que tĂȘm sido encontradas na literatura sobre o peso que cada contraexemplo adicional tem na aceitação de inferĂȘncias.We have developed this thesis with the goal of contributing to a larger understanding of the way in which people use counterexamples during conditional reasoning, when they reason about contents that refer to situations that are common on their daily lives. There is no doubt that people are able to retrieve counterexamples, and many studies attest this ability (e.g. Couto, Quelhas & Juhos, 2010; De Neys & Everaerts, 2008; De Neys, Schaeken & D’ydewalle, 2002; Neys, Schaeken & d'Ydewalle, 2003b;Verschueren, Schaeken, De Neys & d'Ydewalle, 2004). However, the way in which people retrieve and use counterexamples is still in need of some enlightenment. In order to attain our goal, we have developed two sets of experiments, which focus on two important factors. We started by investigating the counterexample retrieval and endorsement of inferences for advice conditionals. On the first experiment, we verified that subjects are capable of generating counterexamples to advice conditionals, but they do it differently for tips and warnings. Following this, on Experiments 2 and 3 we evaluated the impact of the availability (Experiment 2) and the retrieval (Experiment 3) of counterexamples, on the inferences that people draw from advice. Surprisingly, we have concluded that this impact is very little, contrary to what has been found for causal conditionals (e.g. Byrne, Espino & Santamaria, 1999; Couto, Quelhas & Juhos, 2010; Cummins, 1995; Cummins, Lubart, Alksnis & Rist, 1991). Finally, on this first set of experiments, we also investigated the interpretations that people make, based on tips and warnings (Experiment 4), and we concluded that there is an enormous variability of interpretations from advice conditionals. On the second set of experiments, we resorted to causal conditionals to study the impact that retrieving additional counterexamples has on conditional inferences. Experiment 5 shows that retrieving counterexamples is not a fluent process, and that this lack of fluency has a deep impact on the value that people attribute to the retrieved counterexamples, thus leading to a pattern of suppression that is contrary to the information that was recovered. Experiment 6 clarifies that the pattern of suppression reported on Experiment 5 is due to difficulties in the retrieval process. When counterexamples are presented instead of retrieved from memory, the suppression of inferences is compatible with the information that was presented to the participants, that is, more contrerexamples equal more suppression of inferences. On Experiment 7, we confronted counterexamples and the frequency of exceptions, and we concluded that subjects show a preference for probabilistic information, rather than counterexample information, when they make conditional inferences. Overall, our results show three important factors. First, the knowledge retrieved during reasoning has different purposes for different sorts of conditionals, i.e., counterexamples recovered for Advice have a different purpose than counterexamples recovered for causal conditionals. Our results also show that counterexample retrieval is not a fluent process and that people prefer to use probabilistic information. The results above mentioned, aid in explaining the differences that have been found about the weight that additional counterexamples have on inference acceptance rates.Fundação para a CiĂȘncia e a Tecnologia (FCT

    Esa 12th Conference: Differences, Inequalities and Sociological Imagination: Abstract Book

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    Esa 12th Conference: Differences, Inequalities and Sociological Imagination: Abstract Boo

    The psychology of reasoning about preferences and unconsequential decisions

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    International audiencePeople can reason about the preferences of other agents, and predict their behavior based on these preferences. Surprisingly, the psychology of reasoning has long neglected this fact, and focused instead on disinterested inferences, of which preferences are neither an input nor an output. This exclusive focus is untenable, though, as there is mounting evidence that reasoners take into account the preferences of others, at the expense of logic when logic and preferences point to different conclusions. This article summarizes the most recent account of how reasoners predict the behavior and attitude of other agents based on conditional rules describing actions and their consequences, and reports new experimental data about which assumptions reasoners retract when their predictions based on preferences turn out to be false

    The frontiers of state practice in Britain and France: pioneering high speed railway technology and infrastructure

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    The thesis examines British and French state action, that is to say both the characteristic practices of central governments and their underpinning, the working conceptions of public policymaking in technical, political and administrative circles. Taken together, practices and conceptions make up a `referential framework' of public action with distinctive, deep-seated and enduring features in each country. The British and French referential frameworks are deducted from two empirical, comparative case studies of passenger rail transport policy in Britain and France in the years 1965-1993. Use is made of published, archival and interview material, comprising both quantitative and qualitative data, relating to the British and French experiences in the research and development of high speed rolling stock technology (APT and TGV trains) and the planning of new high speed rail infrastructure (Paris-Lyon TGV line and Channel Tunnel Rail Link schemes). The case studies thus constitute windows into the realities of the British and French policy processes. The empirical findings of the case studies point to highly contrasted British and French referential frameworks, of which traditional models of state action cannot adequately take account. For instance, the dominance of often contradictory political and financial imperatives in the British case studies cannot be explained solely in terms of limited government intervention, whilst the prevailing technico-economic rationale in the French case studies does not fully accord with received ideas about the propensity of the French State to intervene in economic life
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