Evolution of statistical analysis in empirical software engineering research: Current state and steps forward

Software engineering research is evolving and papers are increasingly based on empirical data from a multitude of sources, using statistical tests to determine if and to what degree empirical evidence supports their hypotheses. To investigate the practices and trends of statistical analysis in empirical software engineering (ESE), this paper presents a review of a large pool of papers from top-ranked software engineering journals. First, we manually reviewed 161 papers and in the second phase of our method, we conducted a more extensive semi-automatic classification of papers spanning the years 2001--2015 and 5,196 papers. Results from both review steps was used to: i) identify and analyze the predominant practices in ESE (e.g., using t-test or ANOVA), as well as relevant trends in usage of specific statistical methods (e.g., nonparametric tests and effect size measures) and, ii) develop a conceptual model for a statistical analysis workflow with suggestions on how to apply different statistical methods as well as guidelines to avoid pitfalls. Lastly, we confirm existing claims that current ESE practices lack a standard to report practical significance of results. We illustrate how practical significance can be discussed in terms of both the statistical analysis and in the practitioner's context.Comment: journal submission, 34 pages, 8 figure

Psychology of a leader’s managerial activity

This tutorial aid deals with the subject, functions and principles, psychological laws of a leader’s managerial activity, leadership and management, a leader’s role in managerial activity, methods of psychological influence in management systems, individual-and-psychological peculiarities of leader’s personality and his/her role in improving a collective’s social-and-psychological and moral-and psychological climate. For students of all specialities studying psychology course of a leader’s managerial activity

Stereochemistry of heterocycles - XVII. Configuration and conformation of some stereoisomeric 4,5-substituted 2,2-dimethyl-1,3-dioxanes

The configurations and preferred conformations in series of 4,5-dialkyl and 4,5,5-trialkylsubstituted 2,2-dimethyl-1,3-dioxanes were studied. It was proved by PMR spectroscopy that the low-boiling isomers have the cis configuration, while the high-boiling isomers have the trans configuration; moreover, all of the isomers are found in the preferred chair conformation. This conformation experiences a certain amount of distortion, the degree of which depends on the number and character of the substituents in the 5 position. © 1974 Plenum Publishing Corporation

A Method to Assess and Argue for Practical Significance in Software Engineering

A key goal of empirical research in software engineering is to assess practical significance, which answers whether the observed effects of some compared treatments show a relevant difference in practice in realistic scenarios. Even though plenty of standard techniques exist to assess statistical significance, connecting it to practical significance is not straightforward or routinely done; indeed, only a few empirical studies in software engineering assess practical significance in a principled and systematic way. In this paper, we argue that Bayesian data analysis provides suitable tools to assess practical significance rigorously. We demonstrate our claims in a case study comparing different test techniques. The case study\u27s data was previously analyzed (Afzal et al., 2015) using standard techniques focusing on statistical significance. Here, we build a multilevel model of the same data, which we fit and validate using Bayesian techniques. Our method is to apply cumulative prospect theory on top of the statistical model to quantitatively connect our statistical analysis output to a practically meaningful context. This is then the basis both for assessing and arguing for practical significance. Our study demonstrates that Bayesian analysis provides a technically rigorous yet practical framework for empirical software engineering. A substantial side effect is that any uncertainty in the underlying data will be propagated through the statistical model, and its effects on practical significance are made clear. Thus, in combination with cumulative prospect theory, Bayesian analysis supports seamlessly assessing practical significance in an empirical software engineering context, thus potentially clarifying and extending the relevance of research for practitioners

Population status of chuck-will’s-widow (Caprimulgus carolinensis) in the bahamas

The Chuck-will’s-widow (Caprimulgus carolinensis) in the Bahama Islands has been regarded as a rare to uncommon winter visitor. We conducted breeding season surveys on the three largest northern islands (North Andros, Grand Bahama, and Great Abaco) to examine the status of this species. We encountered singing birds on most survey routes on all three islands, suggesting that sizeable breeding populations are widespread in the northern Bahamas with an aggregate estimate of 500–1,000 pairs. Our density estimates were somewhat less than those from the primary range in the United States, suggesting either a lower carrying capacity in the Bahama Islands or recently established populations that have yet to reach carrying capacity. Received 24 August 2009. Accepted 3 January 2010

Lippia citriodora (verbascoside) extract supplementation: Effect on rabbit semen quality in vivo and in vitro

Verbascoside, the main component of Lippia citriodora extract, is one of the most powerful free radical scavengers exhibiting a wide biological activity. In in vivo study 20 adult New Zealand white rabbit bucks were divided into two homogeneous groups, one control (CON) and one verbascoside-supplemented (0.1%) in feed mixture (EXP) and later in vitro effects of verbascoside on the motility aspects of rabbit spermatozoa were analysed. The spermatozoa concentration, ejaculate volume, spermatozoa motility, progressive motility, distance parameters, velocity parameters and type of spermatozoa movement were negatively affected by Lippia citriodora leaves extract after the first 4 weeks of dietary treatment, till the end of experiment (8 weeks). Four weeks after the suspension of feed additive supplementation, all spermatozoa traits values returned to the normality, and in line with CON group. For in vitro findings, ejaculates from 10 male New Zealand white bucks were collected using an artificial vagina. Then it was diluted in physiological saline solution containing different concentrations of verbascoside at the concentration of 0, 0.0024, 0.0219, 0.157, 120.0 mg/ml (Ctrl, VB1, VB2, VB3, VB4 groups, respectively), using a dilution ratio of 1: 4. The obtained data proved that verbascoside at the concentration of 0.0024 and 0.0219 mg/ml had no adverse effect on spermatozoa. Additionally, we found that verbascoside at higher concentrations (0.157 and 120.0 mg/ml) significantly altered all the motility parameters analysed in the experiment. In conclusion a possible negative effect of verbascoside supplementation into feed mixture (0.1%) on semen quality parameters in rabbit bucks as well as in vitro can be stated, obviously considering that target organs of antioxidant activities of phenylpropanoid glycosides are various. In addition it has to be emphasized that the extract showed a reversible action, since the semen traits of treated animals returned to the normality after the dietary administration period

Stereochemistry of heterocycles - XX. Synthesis, properties, and some questions of stereo-chemistry of 2,2,5-substituted 1,3-dioxanes

Some 2,5-dialkyl-2-methyl-1,3-dioxanes and 5-alkyl-2-methyl-2-phenyl-1,3-dioxanes have been synthesized. All the compounds studied consist of epimeric mixtures of geometric isomers the equilibrium in the course of the formation of which is shifted in the direction of the isomers with the diequatorial position of the largest substituents. The predominant conformation of the molecules of both isomers is the chair conformation. The cis isomers of the substances investigated consist of mixtures of conformers. © 1975 Plenum Publishing Corporation

Stereochemistry of heterocycles - XXXIX. Stereochemistry of 2-methyl-5-alkyl-5-phenoxy-1.3-dioxanes

2-Methyl-and 2,5-dialkyl-5-phenoxy-1,3-dioxanes were synthesized and separated into their geometrical isomers by precision rectification. The configuration and conformations of these isomers were determined by PMR spectroscopy. It is shown that the low-boiling trans isomers exist primarily in the chair conformation with an equatorial phenoxy group, whereas the high-boiling cis isomers exist primarily in the chair conformation with an axial phenoxy group. © 1976 Plenum Publishing Corporation

A sequel to the passage about naming rights

Among many countries, "Naming Rights" practices are not rare in business now a days, however, in Japan, these phenomena are very new things, first in 2002, initially on public facilities. Besides administrative and public commercial legal studies did some examine these phenomena, this article tries to discuss as some advertising thoughts, of these origin and basic principles, as the sequel to the same author\u27s main passage.海外では先行する事象がありながらも（注1）、日本で、主として公的な施設の「名前」が、契約によって使用権として対価を伴って売買される、いわゆる「ネーミングライツ（命名権）」として認識され実践が伴ったのは、2002年以降ときわめて近年の事象である（水野、2017）。行政学、私法商法実務などでこれに対する整理も試みられているが、本稿は広告研究としてその価値の泉源を確認し、断片的ながらも、その基底的な認識に向かう議論を試みる続編である

Stereochemistry of heterocycles - XVIII. Configurations and preferred conformations of some 4,5-dialkyl-5-methoxymethyl-and 2,2,4-trimethyl-5-alkyl-5-methoxymethyl-1,3-dioxanes

A group of previously undescribed methoxymethylalkylacetoacetic esters were obtained by the reaction of monochloromethyl ether with sodium salts of alkylacetoacetic esters. The reduction of the new esters with lithium aluminum hydride gave 2-alkyl-2-methoxymethyl-butane-1,3-diols. In connection with the fact that the reduction is stereochemically regulated by the rule of asymmetric induction, the erythro isomers predominate in stereoiso-meric mixtures of the 1, 3-diols. 4,5-Dialkyl-5-methoxymethyl- and 2,2,4-trimethyl-5-alkyl-5-methoxymethyl-1,3-dioxanes (mixtures of the stereoisomers with predominance of the trans isomers) were synthesized by the condensation of 2-alkyl-2-methoxymethylbutane-1,3-diols with formaldehyde and acetone. The stereoisomers were separated by precision rectification, and their configurations and preferred conformations were proved by PMR and IR spectroscopy. The low-boiling isomers of the 1,3-dioxanes under discussion are the trans isomers, while the high-boiling isomers are the cis isomers; the preferred conformation for these isomers is a somewhat distorted chair. © 1974 Plenum Publishing Corporation