Realizing quality improvement through test driven development: results and experiences of four industrial teams

Test-driven development (TDD) is a software development practice that has been used sporadically for decades. With this practice, a software engineer cycles minute-by-minute between writing failing unit tests and writing implementation code to pass those tests. Test-driven development has recently re-emerged as a critical enabling practice of agile software development methodologies. However, little empirical evidence supports or refutes the utility of this practice in an industrial context. Case studies were conducted with three development teams at Microsoft and one at IBM that have adopted TDD. The results of the case studies indicate that the pre-release defect density of the four products decreased between 40% and 90% relative to similar projects that did not use the TDD practice. Subjectively, the teams experienced a 15–35% increase in initial development time after adopting TDD.

Recognizing, assessing, and intervening with problems of professional competence.

Working collaboratively, psychologist educators and trainers at the doctoral, internship, and postdoctoral levels; credentialers; practitioners; and students offer 8 proposals for psychologists to consider in recognizing, assessing, and intervening with problems of professional competence in students and practicing professionals. In the proposals, the authors address the following topics: definitions and categories; preparing the system; self-assessment; remediation; diversity; communication across various levels of the system; confidentiality; and ethical, regulatory, and legal underpinnings. They also propose future directions for the assessment of problems in professional competence in both students and practicing psychologists. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Implicit self-esteem compensation: Automatic threat defense.

Four experiments demonstrated implicit self-esteem compensation (ISEC) in response to threats involving gender identity (Experiment 1), implicit racism (Experiment 2), and social rejection (Experiments 3-4). Under conditions in which people might be expected to suffer a blow to self-worth, they instead showed high scores on 2 implicit self-esteem measures. There was no comparable effect on explicit self-esteem. However, ISEC was eliminated following self-affirmation (Experiment 3). Furthermore, threat manipulations increased automatic intergroup bias, but ISEC mediated these relationships (Experiments 2-3). Thus, a process that serves as damage control for the self may have negative social consequences. Finally, pretest anxiety mediated the relationship between threat and ISEC (Experiment 3), whereas ISEC negatively predicted anxiety among high-threat participants (Experiment 4), suggesting that ISEC may function to regulate anxiety. The implications of these findings for automatic emotion regulation, intergroup bias, and implicit self-esteem measures are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Conflicting social motives in negotiating groups.

Negotiators' social motives (cooperative vs. individualistic) influence their strategic behaviors. In this study, the authors used multilevel modeling and analyses of strategy sequences to test hypotheses regarding how negotiators' social motives and the composition of the group influence group members' negotiation strategies. Four-person groups negotiating a 5-issue mixed-motive decision-making task were videotaped, and the tapes were transcribed and coded. Group composition included 2 homogeneous conditions (all cooperators and all individualists) and 3 heterogeneous conditions (3 cooperators and 1 individualist, 2 cooperators and 2 individualists, 1 cooperator and 3 individualists). Results showed that cooperative negotiators adjusted their use of integrative and distributive strategies in response to the social-motive composition of the group, but individualistic negotiators did not. Results from analyses of strategy sequences showed that cooperators responded more systematically to others' behaviors than did individualists. They also redirected the negotiation depending on group composition. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Modeling and detecting response of micromachining square and circular membranes transducers based on AlN thin film piezoelectric layer

Vibration analysis of square and circular piezoelectric micro ultrasonic transducers (pMUTs) in the 100 kHz range as a function of experimental tools are reported. Analytical and 3D finite element method analysis using Comsol software has been performed to model static, modal and vibration behavior of these membranes. Comparison with standard impedancemeter measurement is shown to assess the performance of Laser Doppler Vibrometry system. Mechanical and electrical characterization and comparison with a model results are presented and discussed. The measured resonances frequencies of membrane can be weak and superimposed on important parasitic signal, which may mask the desired mechanical resonance signal. Our results revealed the real roles of the simulations and the combination of the experimental tools to get measurement accuracy. Subsequently, this piezoelectric micro-transducer was successfully tested as a sounder in air. These investigations offer guidance for the pMUTs design and associated electronic circuit but might at the same time be instructive and beneficial to further sensor applications.

     

On guiding the augmentation of an automated test suite via mutation analysis

Mutation testing has traditionally been used as a defect injection technique to assess the effectiveness of a test suite as represented by a “mutation score.” Recently, mutation testing tools have become more efficient, and industrial usage of mutation analysis is experiencing growth. Mutation analysis entails adding or modifying test cases until the test suite is sufficient to detect as many mutants as possible and the mutation score is satisfactory. The augmented test suite resulting from mutation analysis may reveal latent faults and provides a stronger test suite to detect future errors which might be injected. Software engineers often look for guidance on how to augment their test suite using information provided by line and/or branch coverage tools. As the use of mutation analysis grows, software engineers will want to know how the emerging technique compares with and/or complements coverage analysis for guiding the augmentation of an automated test suite. Additionally, software engineers can benefit from an enhanced understanding of efficient mutation analysis techniques. To address these needs for additional information about mutation analysis, we conducted an empirical study of the use of mutation analysis on two open source projects. Our results indicate that a focused effort on increasing mutation score leads to a corresponding increase in line and branch coverage to the point that line coverage, branch coverage and mutation score reach a maximum but leave some types of code structures uncovered. Mutation analysis guides the creation of additional “common programmer error” tests beyond those written to increase line and branch coverage. We also found that 74% of our chosen set of mutation operators is useful, on average, for producing new tests. The remaining 26% of mutation operators did not produce new test cases because their mutants were immediately detected by the initial test suite, indirectly detected by test suites we added to detect other mutants, or were not able to be detected by any test.

度量和建立合作伙伴满意度、忠诚度从而不断带来收益

合作伙伴的实时反馈是客户关系管理(PR M)的必备要素之一.实时合作伙伴反馈采用调研的形式通过在线、电话、交互式语音应答(IVR)、无线通讯等手段搜集来自终端用户和合作伙伴的实时反馈.此类调研提供针对终端用户及合作伙伴的看法、意向和感受的可行性智能,使企业精益求精:     

If someone is watching,I'll do what I'm asked: mandatoriness,control, and information security

Information security has become increasingly important to organizations. Despite the prevalence of technical security measures, individual employees remain the key link – and frequently the weakest link – in corporate defenses. When individuals choose to disregard security policies and procedures, the organization is at risk. How, then, can organizations motivate their employees to follow security guidelines? Using an organizational control lens, we build a model to explain individual information security precaution-taking behavior. Specific hypotheses are developed and tested using a field survey. We examine elements of control and introduce the concept of ‘mandatoriness,’ which we define as the degree to which individuals perceive that compliance with existing security policies and procedures is compulsory or expected by organizational management. We find that the acts of specifying policies and evaluating behaviors are effective in convincing individuals that security policies are mandatory. The perception of mandatoriness is effective in motivating individuals to take security precautions, thus if individuals believe that management watches, they will comply.     

Effect of grain-boundary crystallization on the high-temperature strength of silicon nitride

Si₃N₄ specimens having the composition 88.7 wt% Si₃N₄-4.9wt% SiO₂-6.4wt% Y₂O₃ (85.1 mol% Si₃N₄-11.1 mol% SiO₂-3.8mol% Y₂O₃) were sintered at 2140° C under 25 atm N₂ for 1 h and then subjected to a 5 h anneal at 1500° C. Crystallization of an amorphous grainboundary phase resulted in the formation of Y₂Si₂O₇. The short-time 1370° C strength of this material was compared with that of material of the same composition having no annealing treatment. No change in strength was noted. This is attributed to the refractory nature of the yttrium-rich grain-boundary phase (apparently identical in both glassy and crystalline phases) and the subsequent domination of the failure process by common processing flaws.Chemical analysis of the medium indicated 5.25 wt% O₂, 0.46 wt% C, 0.8 wt% Al, and expressed in p.p.m. 670 Ca, 30 Cu, 2000 Fe, <2 Ti, 370 Cr, 130 Mg, 90 Mn, <10 V, <20 Zr, 2000 Mo, 240 Ni, 130 Zn, <30 Pb, <60 Sn.     

Can traditional fault prediction models be used for vulnerability prediction?

Finding security vulnerabilities requires a different mindset than finding general faults in software—thinking like an attacker. Therefore, security engineers looking to prioritize security inspection and testing efforts may be better served by a prediction model that indicates security vulnerabilities rather than faults. At the same time, faults and vulnerabilities have commonalities that may allow development teams to use traditional fault prediction models and metrics for vulnerability prediction. The goal of our study is to determine whether fault prediction models can be used for vulnerability prediction or if specialized vulnerability prediction models should be developed when both models are built with traditional metrics of complexity, code churn, and fault history. We have performed an empirical study on a widely-used, large open source project, the Mozilla Firefox web browser, where 21% of the source code files have faults and only 3% of the files have vulnerabilities. Both the fault prediction model and the vulnerability prediction model provide similar ability in vulnerability prediction across a wide range of classification thresholds. For example, the fault prediction model provided recall of 83% and precision of 11% at classification threshold 0.6 and the vulnerability prediction model provided recall of 83% and precision of 12% at classification threshold 0.5. Our results suggest that fault prediction models based upon traditional metrics can substitute for specialized vulnerability prediction models. However, both fault prediction and vulnerability prediction models require significant improvement to reduce false positives while providing high recall.