The first goal of this paper is to empirically explore the relationships between existing object-oriented coupling, cohesion, and inheritance measures and the probability of fault detection in system classes during testing. In other words, we wish to better understand the relationship between existing design measurement in OO systems and the quality of the software developed. The second goal is to propose an investigation and analysis strategy to make these kind of studies more repeatable and comparable, a problem which is pervasive in the literature on quality measurement. Results show that many of the measures capture similar dimensions in the data set, thus reflecting the fact that many of them are based on similar principles and hypotheses. However, it is shown that by using a subset of measures, accurate models can be built to predict which classes contain most of the existing faults. When predicting fault-prone classes, the best model shows a percentage of correct clas...

Measuring structural design properties of a software system, such as coupling, cohesion, or complexity, is a promising approach towards early quality assessments. To use such measurement effectively, quality models are needed that quantitatively describe how these internal structural properties relate to relevant external system qualities such as reliability or maintainability. This chapter has for objective to summarize, in a structured and detailed fashion, the empirical results that have been reported so far with modeling external system quality based on structural design properties in object-oriented systems. We perform a critical review of existing work in order to identify lessons learned regarding the way these studies are performed and reported. Constructive guidelines are also provided to facilitate the work of future studies, thus facilitating the development of an

Database and data model evolution is a significant problem in the highly dynamic business environment that we experience these days. To support the rapidly changing data requirements of agile companies, conceptual data models, which constitute the foundation of database design, should be sufficiently flexible to be able to incorporate changes easily and smoothly. In order to understand what factors drive the maintainability of conceptual data models and to improve conceptual modelling processes, we need to be able to assess conceptual data model properties and qualities in an objective and cost-efficient manner. The scarcity of early available and thoroughly validated maintainability measurement instruments motivated us to define a set of metrics for Entity-Relationship (ER) diagrams, which are a relevant graphical formalism of the conceptual data modelling method. In this paper we show that these objectives and easily calculated metrics, measuring internal properties of ER diagrams related to their structural complexity, can be used as indirect measures (hereafter called indicators) of the maintainability

Abstract. In software engineering it is widely acknowledged that the usage of metrics at the initial phases of the object oriented software life cycle can help designers to make better decisions and to predict external quality attributes, such as maintainability. Following this idea we have carried out three controlled experiments to ascertain if any correlation exists between the structural complexity and the size of UML class diagrams and their maintainability. We used 8 metrics for measuring the structural complexity of class diagrams due to the usage of UML relationships, and 3 metrics to measure their size. With the aim of determining which of these metrics are really relevant to be used as class diagrams maintainability indicators, we present in this work a study based on Principal Component Analysis. The obtained results show that the metrics related to associations, aggregations, generalizations and dependencies, are the most relevant whilst those related to size seem to be redundant.

There has been much controversy in the literature on several issues underlying the construction of parametric software development cost models. For example, it has been argued whether (dis)economies of scale exist in software production, what functional form should be assumed between effort and product size, whether COCOMO factors were useful, and whether the COCOMO factors are independent. Answers to such questions should help software organizations define suitable data collection programs and well-specified cost models. The only way to address these issues and obtain a generalizable conclusion is to investigate them on a large number of consistent data sets. In this paper we use a data set collected by the European Space Agency to perform such an investigation. To ensure a certain degree of consistency in our data, we focus our analysis on a set of space and military projects that represent an important application domain and the largest subset in the database. These projects have be...

This paper examines the information provided to the private sector by central banks. By using the principal component analysis, we investigated the variance of the procedural rules followed by nine major central banks about information treatments. We investigate problems related to the information coming from the central banks by focusing on the quantity and quality perspectives and highlight the methodological complexity of the investigation. We find that a synthetic quantitative index of transparency is not enough to represent the phenomenon since it can result misleading in understanding the behavior of institutionally different central banks associated with the same index values. Keywords: policy. Central bank transparency, principal components, monetary

The aim of the present paper is to propose an analytic framework to identify the major sources of recent social unrest and political instability in some countries of Latin America. Specifically, I wish to provide an alternative methodological schema and propose the use of new measures to determine under which conditions high levels of income inequality—or the “alleged ” increasing income concentration after nearly two decades of structural economic reform—by fueling social discontent, could bring about political instability, thus constituting an important risk for democratic consolidation in the region. In order to elucidate the proposed relationships, I will briefly make reference to two quite interesting and, in some way, contrasting experiences: Brazil and Venezuela.

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