The empirical investigation of Perspective-Based Reading

We consider reading techniques a fundamental means of achieving high quality software. Due to the lack of research in this area, we are experimenting with the application and comparison of various reading techniques. This paper deals with our experiences with a family of reading techniques known as Perspective-Based Reading (PBR), and its application to requirements documents. The goal of PBR is to provide operational scenarios where members of a review team read a document from a particular perspective, e.g., tester, developer, user. Our assumption is that the combination of different perspectives provides better coverage of the document, i.e., uncovers a wider range of defects, than the same number of readers using their usual technique.To test the effectiveness of PBR, we conducted a controlled experiment with professional software developers from the National Aeronautics and Space Administration/Goddard Space Flight Center (NASA/GSFC) Software Engineering Laboratory (SEL). The subjects read two types of documents, one generic in nature and the other from the NASA domain, using two reading techniques, a PBR technique and their usual technique. The results from these experiments, as well as the experimental design, are presented and analyzed. Teams applying PBR are shown to achieve significantly better coverage of documents than teams that do not apply PBR.We thoroughly discuss the threats to validity so that external replications can benefit from the lessons learned and improve the experimental design if the constraints are different from those posed by subjects borrowed from a development organization.     

Implementation techniques for the vehicle routing problem

Six methods for implementing the widely used Clarke-Wright algorithm for the vehicle routing problem (VRP) are presented and compared. Fifty-five large test problems are used to compare the methods. The methods involve alternative ways to access adjacency information in both low and high density problems. The results clearly establish methods of choice for VRP problems with given characteristics.     

Hardened portland cement pastes of low porosity III. Degree of hydration. Expansion of paste. Total porosity

The degree of hydration, the expansion during hydration, and the total porosity of low-porosity portland cement pastes were investigated at hydration times ranging from 1 hour to 180 days. The effects of the type of cement (Type I and II), the grinding aid, the surface of the cement, the water-cement ratio (0.2 and 0.3), and the temperature of hydration (5°, 25° and 50°C) were determined.     

Parental communication deviance and schizophrenia: A cross-cultural comparison of Mexican- and Anglo-Americans.

Levels of parental communication deviance (CD), as measured on the Thematic Apperception Test (TAT), were compared among families of schizophrenic patients in two culturally distinct groups. Spanish-speaking Mexican-American parents of schizophrenics completed the TAT in their native language, and CD was coded from their stories by a Spanish-speaking rater. Mexican-American parents had levels of CD that were nearly identical to those of a carefully matched sample of English-speaking Anglo-American parents. Factor scores that measure distinct subtypes of CD also did not differ across groups. The data suggest that levels of CD, despite discriminating between parents of schizophrenics and nonschizophrenics, do not vary across different languages and cultures. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A note on lee and schachter's algorithm for delaunay triangulation

Lee and Schachter have presented an algorithm for the Delaunay triangulation of a set of points whose convex hull is a rectangular region. An addendum to that algorithm is presented which gives the Delaunay triangulation of a set of points with an arbitrary convex hull. Timing results are also given.     

Impact of questionnaire length, follow-up methods, and geographical location on response rate to a mail survey.

Assessed the impact of 2 levels of questionnaire length, 4 follow-up methods, and 8 heterogeneous geographical areas on response rate to a mail survey. Questionnaires were mailed to a large random sample of telephone customers. For each geographical location, 264 customers were drawn and equally divided among the 8 experimental conditions. No significant differences in response rate occurred between a short, 4-page questionnaire and a long, 6-page questionnaire. However, the telephone reminder produced the best results, post reminder the second best results, and telephone interviews both with and without prior alert produced the poorest results. There were significant Follow-Up * Geographical Area interactions, suggesting a market segmentation strategy. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Accuracy of interviewers, certified public accountants, and students in identifying the interests of accountants.

Developed a 57-item modified forced-choice stereotype accuracy test to determine how well 14 interviewers, 23 Certified Public Accountants (CPA) who interview, and 20 male undergraduates could identify the interests of accountants. There were no differences in accuracy between the groups, but factor analysis revealed 2 clusters, 1 of CPAs and the other containing mostly interviewers and students, which have different perceptions of accountant's interests. If selection depends on the goodness of fit to a stereotype, then members of the 2 clusters would select different applicants for the position of accountant. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

An Industrial Psychologist's Lament: The Problem of Shrinking Sample Size.

Illustrates with a specific example the problem of the shrinking sample in experimentation. It is contended that this is a problem faced rather rarely by psychologists engaged in activities other than industrial psychology. The history of the sample involved in a study conducted by the authors at the Minnesota Mining and Manufacturing Company is outlined. It is argued that the volunteer subjects (sales personnel) became less cooperative when confronted with the actual test-taking task. Also, criterion information was unavailable for the sample population. Lastly, the sales personnel for whom test information was available were not necessarily the same as for those for whom criterion information was available, and vice versa. It is concluded that in spite of all this, the study was conducted and fairly meaningful and helpful results were obtained. (PsycINFO Database Record (c) 2010 APA, all rights reserved)