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- Grindal, Mats, et al.
(författare)
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An Evaluation of Combination Strategies for Test Case Selection
- 2006
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Ingår i: Empirical Software Engineering. - : Springer. - 1382-3256 .- 1573-7616. ; 11:4, s. 583-611
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Tidskriftsartikel (refereegranskat)abstract
- This paper presents results from a comparative evaluation of five combination strategies. Combination strategies are test case selection methods that combine “interesting” values of the input parameters of a test subject to form test cases. This research comparatively evaluated five combination strategies; the All Combination strategy (AC), the Each Choice strategy (EC), the Base Choice strategy (BC), Orthogonal Arrays (OA) and the algorithm from the Automatic Efficient Test Generator (AETG). AC satisfies n-wise coverage, EC and BC satisfy 1-wise coverage, and OA and AETG satisfy pair-wise coverage. The All Combinations strategy was used as a “gold standard” strategy; it subsumes the others but is usually too expensive for practical use. The others were used in an experiment that used five programs seeded with 128 faults. The combination strategies were evaluated with respect to the number of test cases, the number of faults found, failure size, and number of decisions covered. The strategy that requires the least number of tests, Each Choice, found the smallest number of faults. Although the Base Choice strategy requires fewer test cases than Orthogonal Arrays and AETG, it found as many faults. Analysis also shows some properties of the combination strategies that appear significant. The two most important results are that the Each Choice strategy is unpredictable in terms of which faults will be revealed, possibly indicating that faults are found by chance, and that the Base Choice and the pair-wise combination strategies to some extent target different types of faults.
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| 2. |
- Grindal, Mats, et al.
(författare)
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An Evaluation of Combination Strategies for Test Case Selection
- 2003
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- In this report we present the results from a comparative evaluation of five combination strategies. Combination strategies are test case selection methods that combine interesting values of the input parameters of a test object to form test cases. One of the investigated combination strategies, namely the Each Choice strategy, satisfies 1-wise coverage, i.e., each interesting value of each parameter is represented at least once in the test suite. Two of the strategies, the Orthogonal Arrays and Heuristic Pair-Wise strategies both satisfy pair-wise coverage, i.e., every possible pair of interesting values of any two parameters are included in the test suite. The fourth combination strategy, the All Values strategy, generates all possible combinations of the interesting values of the input parameters. The fifth and last combination strategy, the Base Choice combination strategy, satisfies 1-wise coverage but in addition makes use of some semantic information to construct the test cases. Except for the All Values strategy, which is only used as a reference point with respect to the number of test cases, the combination strategies are evaluated and compared with respect to number of test cases, number of faults found, test suite failure density, and achieved decision coverage in an experiment comprising five programs, similar to Unix commands, seeded with 131 faults. As expected, the Each Choice strategy finds the smallest number of faults among the evaluated combination strategies. Surprisingly, the Base Choice strategy performs as well, in terms of detecting faults, as the pair-wise combination strategies, despite fewer test cases. Since the programs and faults in our experiment may not be representative of actual testing problems in an industrial setting, we cannot draw any general conclusions regarding the number of faults detected by the evaluated combination strategies. However, our analysis shows some properties of the combination strategies that appear significant in spite of the programs and faults not being representative. The two most important results are that the Each Choice strategy is unpredictable in terms of which faults will be detected, i.e., most faults found are found by chance, and that the Base Choice and the pair-wise combination strategies to some extent target different types of faults.
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| 3. |
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| 4. |
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| 5. |
- Johansson, Inger, 1943-, et al.
(författare)
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Balancing integrity vs. risk of falling - Nurses experiences of caring for elderly people with dementia in nursing homes
- 2009
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Ingår i: Journal of Research in Nursing. - : SAGE Publications. - 1744-9871 .- 1744-988X. ; 14:1, s. 61-73
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Tidskriftsartikel (refereegranskat)abstract
- Dementia is recognized as being a major risk for falls that cause suffering and increase dependency for the individual. The purpose of this study was to explore registered nurses and nurse assistants experiences of caring for elderly people with dementia who are at risk of falling, and factors that contribute or reduce falls in this group. A phenomenographic design was chosen. Ten nurses and 18 nurse assistants with experience of fall events were strategically selected for a recorded interview. The informants were chosen from 10 nursing homes in Sweden and Norway. They were asked to describe a fall situation they had been involved in when caring for elderly people with dementia. The findings shed light on an ethical dilemma in the main category Balancing integrity and autonomy versus risk of falling � which was comprehensively related to two descriptive categories. The first one was Adjusting to the older person�s condition� with the concepts of forgetfulness, anxiety and confusion, ability to express oneself and understand, bodily build and function. The second category was Adjusting the care environment�, comprising these conceptions: the physical environment, the psychosocial environment, organization and human resources. Based on the staff�s perceived difficulties in preventing falls in elderly people with dementia, there is a need for additional support or professional supervision in their work to enhance possibilities for successful fall prevention.
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| 6. |
- Larsson, Birgitta, et al.
(författare)
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Extracts of ECL-cell granules/vesicles and of isolated ECL cells from rat oxyntic mucosa evoke a Ca2+ second messenger response in osteoblastic cells
- 2001
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Ingår i: Regulatory Peptides. ; 97:2-3, s. 153-161
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Tidskriftsartikel (refereegranskat)abstract
- Surgical removal of the acid-producing part of the stomach (oxyntic mucosa) reduces bone mass through mechanisms not yet fully understood. The existence of an osteotropic hormone produced by the so-called ECL cells has been suggested. These cells, which are numerous in the oxyntic mucosa, operate under the control of circulating gastrin. Both gastrin and an extract of the oxyntic mucosa decrease blood calcium and stimulate Ca2+ uptake into bone. Conceivably, gastrin lowers blood calcium indirectly by releasing a hypothetical hormone from the ECL cells. The present study investigated, by means of fura-2 fluorometry, the effect of extracts of preparations enriched in ECL cell granules/vesicles from rat oxyntic mucosa on mobilization of intracellular Ca2+ in three osteoblast-like cell lines, UMR-106.01, MC3T3-E1 and Saos-2, and of extracts of isolated ECL cells in UMR-106.01 cells. The extracts were found to induce a dose-related rapid increase in intracellular Ca2+ concentrations in the osteoblast-like cells. The response was not due to histamine or pancreastatin, known ECL cell constituents, and could be abolished by pre-digesting the extracts with exo-aminopeptidase. The results show that the increase in [Ca2+](i) reflects a mobilization of Ca2+ from the endoplasmic reticulum. The observation of an increase in [Ca2+](i) also in murine embryonic fibroblasts show that the response is not limited to osteoblastic cells. The finding that the extracts evoked a typical Ca2+ -mediated second messenger response in osteoblastic cells provides evidence for the existence of a novel osteotropic peptide hormone (gastrocalcin), produced in the ECL cells, and supports the view that gastrectomy-induced osteopathy may reflect a lack of this hormone.
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| 7. |
- Lindström, Birgitta, et al.
(författare)
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Generating Trace-Sets for Model-Based Testing
- 2007
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Ingår i: Proceedings 18th IEEE International Symposiumon Software Reliability Engineering. - : IEEE. - 9780769530246 - 0769530249 ; , s. 171-180
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Konferensbidrag (refereegranskat)abstract
- Model-checkers are powerful tools that can find individual traces through models to satisfy desired properties. These traces provide solutions to a number of problems. Instead of individual traces, software testing needs sets of traces that satisfy coverage criteria. Finding a trace set in a large model is difficult because model checkers generate single traces and use a lot of memory. Space and time requirements of modelchecking algorithms grow exponentially with respect to the number of variables and parallel automata of the model being analyzed. We present a method that generates a set of traces by iteratively invoking a model checker. The method mitigates the memory consumption problem by dynamically building partitions along the traces. This method was applied to a testability case study, and it generated the complete trace set, while ordinary model-checking could only generate 26%.
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| 8. |
- Lindström, Birgitta, et al.
(författare)
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Generating Trace-Sets for Model-based Testing
- 2007
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Ingår i: Proceedings of the 18th IEEE International Symposium on Software Reliability. - 9780769530246 ; , s. 171-180
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Konferensbidrag (refereegranskat)abstract
- Model-checkers are powerful tools that can find individual traces through models to satisfy desired properties. These traces provide solutions to a number of problems. Instead of individual traces, software testing needs sets of traces that satisfy coverage criteria. Finding a trace set in a large model is difficult because model checkers generate single traces and use a lot of memory. Space and time requirements of model-checking algorithms grow exponentially with respect to the number of variables and parallel automata of the model being analyzed. We present a method that generates a set of traces by iteratively invoking a model checker. The method mitigates the memory consumption problem by dynamically building partitions along the traces. This method was applied to a testability case study, and it generated the complete trace set, while ordinary model-checking could only generate 26%.
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| 9. |
- Lindström, Birgitta, et al.
(författare)
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Generating Trace-Sets for Model-based Testing
- 2007
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Ingår i: The 18th IEEE International Symposium on Software Reliability (ISSRE '07). ; , s. 171-180
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Konferensbidrag (populärvet., debatt m.m.)abstract
- Model-checkers are powerful tools that can find individual traces through models to satisfy desired properties. These traces provide solutions to a number of problems. Instead of individual traces, software testing needs sets of traces that satisfy coverage criteria. Finding a trace set in a large model is difficult because model checkers generate single traces and use a lot of memory. Space and time requirements of modelchecking algorithms grow exponentially with respect to the number of variables and parallel automata of the model being analyzed. We present a method that generates a set of traces by iteratively invoking a model checker. The method mitigates the memory consumption problem by dynamically building partitions along the traces. This method was applied to a testability case study, and it generated the complete trace set, while ordinary model-checking could only generate 26%.
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| 10. |
- Lindström, Birgitta, et al.
(författare)
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Model-Checking with Insufficient Memory Resources
- 2006
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Resource limitations is a major problem in model checking. Space and time requirements of model-checking algorithms grow exponentially with respect to the number of variables and parallel automata of the analyzed model. We present a method that is the result of experiences from a case study. It has enabled us to analyze models with much bigger state-spaces than what was possible without our method. The basic idea is to build partitions of the state-space of an analyzed system by iterative invocations of a model-checker. In each iteration the partitions are extended to represent a larger part of the state space, and if needed the partitions are further partitioned. Thereby the analysis problem is divided into a set of subproblems that can be analyzed independently of each other. We present how the method, implemented as a meta algorithm on-top of the Uppaal tool, has been applied in the case study.
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