Using blind analysis for software engineering experiments

Context: In recent years there has been growing concern about conflicting experimental results in empirical software engineering. This has been paralleled by awareness of how bias can impact research results. Objective: To explore the practicalities of blind analysis of experimental results to reduce bias. Method : We apply blind analysis to a real software engineering experiment that compares three feature weighting approaches with a na ̈ıve benchmark (sample mean) to the Finnish software effort data set. We use this experiment as an example to explore blind analysis as a method to reduce researcher bias. Results: Our experience shows that blinding can be a relatively straightforward procedure. We also highlight various statistical analysis decisions which ought not be guided by the hunt for statistical significance and show that results can be inverted merely through a seemingly inconsequential statistical nicety (i.e., the degree of trimming). Conclusion: Whilst there are minor challenges and some limits to the degree of blinding possible, blind analysis is a very practical and easy to implement method that supports more objective analysis of experimental results. Therefore we argue that blind analysis should be the norm for analysing software engineering experiments

School Climate Development Survey

Over the last twenty-five years the Consortium on Chicago School Research has engaged in systematic study of more than 400 Chicago Public Schools to determine organizational traits that are related to improvement in student learning. This effort was designed to help explain widely divergent levels of student success between very similar schools in the Chicago system. Initial discussions with educators at all levels, reviews of previous research, pilot studies, and field studies led to the identification of five school contextual factors – the 5Essential Supports – determined to be critical to school success: (1) effective leaders, (2) collaborative teachers, (3) involved families, (4) supportive environment, and (5) ambitious instruction. The framework of the 5Essential Supports served as a theoretical basis for a survey effort designed to measures and report on facets of school culture that could then be used by school leaders and practitioners to guide school improvement efforts. Research related to the 5Essential Supports consistently demonstrates a strong relationship between the presence of these supports and gains in student achievement. Led by Dr. James McMillan and Dr. Charol Shakeshaft from VCU’s School of Education, the purpose of this MERC study was (1) to develop a shortened version of the 5Essentials staff climate survey for the Metropolitan Educational Research Consortium schools, (2) to pilot test the new survey with teachers and administrators, and (3) to determine effective methods of dissemination to support schools use f the survey data for school improvement purposes. The piloting and validation phase of the study demonstrated that the core constructs underlying the 5Essentials maintained high levels of validity and reliability in the shortened version. MERC also piloted and received feedback from school leaders on formats for reporting school climate results

Objectification and transgender jurisprudence: the dictionary as quasi-statute

This paper analyzes defi nitional issues raised by terms such as 'man' and 'woman' in transgender jurisprudence, focussing on the Court of First Instance decision in W v Registrar of Marriages. Courts frequently seek guidance on ordinary meaning in standard works of lexicography. But this objectifies the trans party by treating so-called “ordinary” meaning and the dictionary defi nition as determinative.published_or_final_versio

Quasi-optimum design of a six degree of freedom moving base simulator control system

The design of a washout control system for a moving base simulator is treated by a quasi-optimum control technique. The broad objective of the design is to reproduce the sensed motion of a six degree of freedom simulator as accurately as possible without causing the simulator excursions to exceed specified limits. A performance criterion is established that weights magnitude and direction errors in specific force and in angular velocity and attempts to maintain the excursion within set limits by penalizing excessive excursions. A FORTRAN routine for relizing the washout law was developed and typical time histories using the washout routine were simulated for a range of parameters in the penalty- and weighting-functions. These time histories and the listing of the routine are included in the report

Assessing Acquiescence in Surveys Using Positively and Negatively Worded Questions

The purpose of this study was to assess the impact of acquiescence on both positively and negatively worded questions, both when unidimensionality was assumed and when it was not. To accomplish this, undergraduate student responses to a previously validated survey of student engagement were used to compare several models of acquiescence, using a priori goodness-offit statistics as evidence for model fit, in order to develop a model that adequately accounted for acquiescence bias. Using a true experimental design, undergraduate students from a variety of classes at a large, urban university were randomly assigned to one of three versions of the same survey of student engagement (all positively worded items, all negatively worded items, an equal balance of both positively and negatively worded items). Structural equation modeling was used to analyze the results. Although the presence of acquiescence was confirmed for both positively and negatively worded items, it was not consistent by content scale or item polarization. This suggests that there may be an interaction between item polarization and content that may cause acquiescence to be present or absent. The scales that did not show acquiescence on the balanced survey portrayed a split factor loading based upon item polarization. Further, the splitting of factor loadings by item polarization was not due to acquiescence, suggesting that something other than acquiescence is causing the loadings to split. Further research is needed to develop models and/or methods to better assess and control for acquiescence. Although demographic groups were compared by gender and race/ethnicity to assess if different groups acquiesced differently, using multi-group confirmatory factor analysis, many of the models did not converge. The findings of this study were limited by the nature of the sample size. Additional research is needed to determine if acquiescence differs by group membership

Changing Soviet Oil Interests: Implications for the Middle East

Best available estimates reveal that the Soviet Union will not be able to produce sufficient oil to meet her needs. While this deficiency can be met several ways, one logical alternative, on which Moscow has already embarked, is the exploitation of Mideast oil

Art & Ecology in the West of Ireland: Finding, Understanding, & Creating Relationships between Artistic Practice and the Burren

In this essay I describe how my engagement with the Burren in the west of Ireland became the foundation for my doctoral research and subsequently the development of an Art & Ecology Masters in Fine Art. I present a brief overview of the unique ecology of the Burren, including its geological, archaeological and agricultural history, so as to provide a context for both my artistic inquiry and the Burren College of Art students’ immersive experience. I then discuss my collaborative practice with small birds and honeybees as a means for exploring and expanding the traditional notion of ecology through artistic practice. This essay, illustrated with original photographs, is a consideration of the importance of biodiversity, the conservation of priority species through artificial habitats, and argues that artists can propose solutions and engender change through their practices. As both an artist and an educator, I seek to help students foster a deeper understanding of the interconnectedness of and humanity’s reliance upon ecological systems, and to know that as artists, they can be catalysts for environmental change

Aspects of urban unemployment in Uganda.

From the early years of this century, a periodic problem besetting development in Uganda has been shortage of labour, a shortage which was shared by the Baganda farmers who came to depend on hired labour. From the 1920s this shortage was met by increasing immigration of labour from countries bordering on Uganda, notably Ruanda-Urundi, by revruiting agencies and by a growing flow of' immigrants from West Nile, Kigezi and Ankole and later from other areas of Uganda (Powesland 1954). From the middle 1950s the annual reports of the Labour Department begin to mention periodic surpluses of the unskilled labour in towns, co-existing with shortages of labour elsewhere. The last reports of 1959 and 1960 speak of general surplus of all labour in towns, except the most highly skilled, and or growing numbers of school leavers coming onto the labour market with inadequate qualifications for the rising standards expected by employers. The reports qualify this by adding the unemployment was not a serious urban problem because the unemployed were able to return to their homes when they failed to find work

Attentional load and sensory competition in human vision: Modulation of fMRI responses by load fixation during task-irrelevant stimulation in the peripheral visual field.

Perceptual suppression of distractors may depend on both endogenous and exogenous factors, such as attentional load of the current task and sensory competition among simultaneous stimuli, respectively. We used functional magnetic resonance imaging (fMRI) to compare these two types of attentional effects and examine how they may interact in the human brain. We varied the attentional load of a visual monitoring task performed on a rapid stream at central fixation without altering the central stimuli themselves, while measuring the impact on fMRI responses to task-irrelevant peripheral checkerboards presented either unilaterally or bilaterally. Activations in visual cortex for irrelevant peripheral stimulation decreased with increasing attentional load at fixation. This relative decrease was present even in V1, but became larger for successive visual areas through to V4. Decreases in activation for contralateral peripheral checkerboards due to higher central load were more pronounced within retinotopic cortex corresponding to 'inner' peripheral locations relatively near the central targets than for more eccentric 'outer' locations, demonstrating a predominant suppression of nearby surround rather than strict 'tunnel vision' during higher task load at central fixation. Contralateral activations for peripheral stimulation in one hemifield were reduced by competition with concurrent stimulation in the other hemifield only in inferior parietal cortex, not in retinotopic areas of occipital visual cortex. In addition, central attentional load interacted with competition due to bilateral versus unilateral peripheral stimuli specifically in posterior parietal and fusiform regions. These results reveal that task-dependent attentional load, and interhemifield stimulus-competition, can produce distinct influences on the neural responses to peripheral visual stimuli within the human visual system. These distinct mechanisms in selective visual processing may be integrated within posterior parietal areas, rather than earlier occipital cortex